Beginner
Abbreviations
#acronyms
#vocabulary
Expand the Abbreviation
12 exercises — match the abbreviation to its full form and read the usage note. API, SSH, ORM, CDN, TLS, CORS, JWT, CI/CD, DNS, SLA, HTTP, YAML.
0 / 32 completed
1 / 32
What does API stand for?
Application Programming Interface — a set of rules and contracts that allow different software applications to communicate with each other. You may see it in: "We expose a REST API", "the third-party API returns JSON", "rate-limiting on the public API".
2 / 32
What does SSH stand for?
Secure Shell — a cryptographic network protocol for operating network services securely over an unsecured network. Most commonly used for remote server login: "SSH into the server", "add your SSH key to authorized_keys".
3 / 32
What does ORM stand for?
Object-Relational Mapping — a technique that lets you interact with a database using object-oriented code instead of raw SQL. Examples include SQLAlchemy (Python), Hibernate (Java), ActiveRecord (Ruby), Prisma (Node.js). "We use an ORM to avoid writing raw queries."
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What does CDN stand for?
Content Delivery Network — a geographically distributed group of servers that work together to provide fast delivery of internet content. "We serve static assets through a CDN", "CDN edge caches the images closest to the user", "cache invalidation on the CDN after each deploy".
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What does TLS stand for?
Transport Layer Security — a cryptographic protocol that provides end-to-end security for communications over a network. Successor to SSL. "Enforce TLS 1.2 minimum", "TLS termination at the load balancer", "the TLS certificate expired".
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What does CORS stand for?
Cross-Origin Resource Sharing — a browser mechanism that allows or restricts web applications running at one origin to make requests to a different origin. "CORS headers are missing", "configure CORS to allow our frontend domain", "the CORS preflight request fails".
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What does JWT stand for?
JSON Web Token — a compact, URL-safe means of representing claims to be transferred between two parties. Pronounced "jot" (not J-W-T). "Sign the JWT with the private key", "check the JWT expiry time", "never store sensitive data in the JWT payload — it is base64-encoded, not encrypted".
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What does CI/CD stand for?
Continuous Integration / Continuous Delivery OR Deployment — CI/CD is a combined term. "CD" can legitimately mean either Continuous Delivery (code is always in a deployable state but humans trigger deploys) or Continuous Deployment (every passing CI build is automatically deployed to production). Both expansions are correct; teams define which they mean. CI always means Continuous Integration — automated testing on every commit.
9 / 32
What does DNS stand for?
Domain Name System — the internet's phonebook: it translates human-readable domain names (coderslingo.com) into machine-readable IP addresses. "DNS propagation takes up to 48 hours", "check the DNS record with nslookup", "TTL on the DNS entry is set to 300 seconds".
10 / 32
What does SLA stand for?
Service Level Agreement — a contract between a service provider and a customer defining the level of service expected. Key related terms: SLO (Service Level Objective — the target within the SLA, e.g. 99.9% uptime) and SLI (Service Level Indicator — the actual measured metric). "We breached the SLA", "the SLO is 99.95% monthly uptime", "latency is the primary SLI for this service".
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What does HTTP stand for?
HyperText Transfer Protocol — the foundation of data communication on the web. HTTP/1.1 (1997), HTTP/2 (2015), HTTP/3 (2022, uses QUIC over UDP). HTTPS adds TLS. "Return a 404 HTTP status", "upgrade to HTTP/2 for multiplexing", "enforce HTTPS redirect".
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What does YAML stand for?
YAML Ain't Markup Language — a recursive acronym (the "Y" stands for YAML itself). YAML is a human-readable data serialisation format used heavily in config files (Docker Compose, Kubernetes manifests, GitHub Actions workflows, Ansible playbooks). Pronounced "yam-ul". "The GitHub Actions workflow is a YAML file", "Kubernetes uses YAML manifests", "indentation errors in YAML can break the entire config".
13 / 32
Sarah: 'Hey team, the build failed again! The error message mentions a '403' status code. I'm not sure what that means in this context—should we investigate the authentication setup or something related to permissions? Mark: 'I think it might be a CORS issue.' Which of the following best explains Mark's suggestion?
The '403 Forbidden' HTTP status code specifically indicates that the client does not have permission to access the requested resource. CORS (Cross-Origin Resource Sharing) violations are a frequent cause of this error when JavaScript running from one domain attempts to access resources on another domain. Therefore, Mark is correctly suggesting to investigate whether the build process is attempting to access external resources in a way restricted by CORS policies – a common issue in modern web development.
14 / 32
Mark: 'We're seeing a high latency on the API calls from our mobile app. The monitoring dashboard shows increased response times for requests to the /users endpoint. Initial investigation suggests it might be related to database queries... but I'm not entirely clear on what 'cold cache' means in this context. Should we focus on optimizing the SQL query, or is there something else impacting performance?This question tests understanding of a common performance issue terminology. A 'cold cache' refers to data that hasn't been recently accessed or refreshed in the application server's memory (or a CDN). While optimizing database queries is important for long-term performance, addressing the cold cache – which directly impacts retrieval speed – is the immediate priority when dealing with high latency. Options A and B misinterpret the role of caching; option D incorrectly assumes it's just jargon, and option C highlights the correct prioritization.
15 / 32
Mark: 'We've received a notification from the monitoring system – 'High CPU Utilization' on Server B. The application is reporting intermittent slowdowns during peak hours. We suspect it might be related to our image processing service. I need some clarification on what 'thread pool exhaustion' means in this context; we're currently running with a default size, and I'm wondering if scaling that up would resolve the issue.' Which of the following best describes Mark's concern?Mark is worried about the application's ability to handle concurrent requests. Thread pool exhaustion refers to a situation where the number of threads available in a thread pool exceeds the number of incoming requests, leading to delays and slowdowns as tasks queue up waiting for processing time. The default size of the thread pool likely isn't sufficient to cope with peak loads, causing this issue; scaling it would provide more capacity.
16 / 32
Mark: 'The new deployment is running slowly. The logs show a lot of 'Connection Refused' errors when our frontend tries to access the backend API. I'm not sure if it's something to do with the load balancer configuration or the server itself.' Which of the following options best reflects Mark's concern?A. The database is overloaded and needs scaling.
B. The load balancer isn't correctly routing traffic to the backend servers, potentially due to a misconfiguration.
C. The API code contains inefficient algorithms causing excessive processing time.
D. The application server's CPU resources are being exhausted.
Mark is experiencing 'Connection Refused' errors when accessing the API. This strongly suggests an issue with network connectivity or routing – specifically, the load balancer isn't directing requests to the available backend servers. The other options (database overload, inefficient code, and CPU exhaustion) are potential issues but less directly related to the immediate symptom described in the log message. Therefore, option B is the most accurate reflection of his concern.
17 / 32
During a code review for a new feature that integrates with a third-party payment gateway, Liam comments: 'The response from the API is returning a
A. The authentication token used to access the payment gateway API has expired or been revoked.
B. The third-party payment gateway is experiencing temporary downtime or high traffic volume, leading to service unavailability.
C. There's a bug in our code that's causing excessive requests to be sent to the payment gateway API.
D. The network connection between our application and the payment gateway has been disrupted.
503 Service Unavailable error intermittently. It seems like the external service might be overloaded.' Considering this context, which of the following best explains Liam's concern? A. The authentication token used to access the payment gateway API has expired or been revoked.
B. The third-party payment gateway is experiencing temporary downtime or high traffic volume, leading to service unavailability.
C. There's a bug in our code that's causing excessive requests to be sent to the payment gateway API.
D. The network connection between our application and the payment gateway has been disrupted.
Liam is observing an HTTP status code indicating that the service he's relying on (the third-party payment gateway) is temporarily unable to handle requests. A
503 Service Unavailable error specifically points to resource constraints or downtime on the external server, making option B the most accurate explanation of his concern. Options A, C and D represent alternative possibilities but are less directly related to the stated status code.18 / 32
Sarah: 'Hey team, the build failed again! The error message mentions a '403' status code. I'm not sure what that means in this context—should we investigate the authentication setup or something related to permissions? Mark: 'I think it might be a CORS issue.' Which of the following best explains Mark's suggestion?
The '403 Forbidden' HTTP status code specifically indicates that the client does not have permission to access the requested resource. CORS (Cross-Origin Resource Sharing) violations are a frequent cause of this error when JavaScript running from one domain attempts to access resources on another domain. Therefore, Mark is correctly suggesting to investigate whether the build process is attempting to access external resources in a way restricted by CORS policies – a common issue in modern web development.
19 / 32
Mark: 'We're seeing a high latency on the API calls from our mobile app. The monitoring dashboard shows increased response times for requests to the /users endpoint. Initial investigation suggests it might be related to database queries... but I'm not entirely clear on what 'cold cache' means in this context. Should we focus on optimizing the SQL query, or is there something else impacting performance?This question tests understanding of a common performance issue terminology. A 'cold cache' refers to data that hasn't been recently accessed or refreshed in the application server's memory (or a CDN). While optimizing database queries is important for long-term performance, addressing the cold cache – which directly impacts retrieval speed – is the immediate priority when dealing with high latency. Options A and B misinterpret the role of caching; option D incorrectly assumes it's just jargon, and option C highlights the correct prioritization.
20 / 32
Mark: 'We've received a notification from the monitoring system – 'High CPU Utilization' on Server B. The application is reporting intermittent slowdowns during peak hours. We suspect it might be related to our image processing service. I need some clarification on what 'thread pool exhaustion' means in this context; we're currently running with a default size, and I'm wondering if scaling that up would resolve the issue.' Which of the following best describes Mark's concern?Mark is worried about the application's ability to handle concurrent requests. Thread pool exhaustion refers to a situation where the number of threads available in a thread pool exceeds the number of incoming requests, leading to delays and slowdowns as tasks queue up waiting for processing time. The default size of the thread pool likely isn't sufficient to cope with peak loads, causing this issue; scaling it would provide more capacity.
21 / 32
Mark: 'The new deployment is running slowly. The logs show a lot of 'Connection Refused' errors when our frontend tries to access the backend API. I'm not sure if it's something to do with the load balancer configuration or the server itself.' Which of the following options best reflects Mark's concern?A. The database is overloaded and needs scaling.
B. The load balancer isn't correctly routing traffic to the backend servers, potentially due to a misconfiguration.
C. The API code contains inefficient algorithms causing excessive processing time.
D. The application server's CPU resources are being exhausted.
Mark is experiencing 'Connection Refused' errors when accessing the API. This strongly suggests an issue with network connectivity or routing – specifically, the load balancer isn't directing requests to the available backend servers. The other options (database overload, inefficient code, and CPU exhaustion) are potential issues but less directly related to the immediate symptom described in the log message. Therefore, option B is the most accurate reflection of his concern.
22 / 32
During a code review for a new feature that integrates with a third-party payment gateway, Liam comments: 'The response from the API is returning a
A. The authentication token used to access the payment gateway API has expired or been revoked.
B. The third-party payment gateway is experiencing temporary downtime or high traffic volume, leading to service unavailability.
C. There's a bug in our code that's causing excessive requests to be sent to the payment gateway API.
D. The network connection between our application and the payment gateway has been disrupted.
503 Service Unavailable error intermittently. It seems like the external service might be overloaded.' Considering this context, which of the following best explains Liam's concern? A. The authentication token used to access the payment gateway API has expired or been revoked.
B. The third-party payment gateway is experiencing temporary downtime or high traffic volume, leading to service unavailability.
C. There's a bug in our code that's causing excessive requests to be sent to the payment gateway API.
D. The network connection between our application and the payment gateway has been disrupted.
Liam is observing an HTTP status code indicating that the service he's relying on (the third-party payment gateway) is temporarily unable to handle requests. A
503 Service Unavailable error specifically points to resource constraints or downtime on the external server, making option B the most accurate explanation of his concern. Options A, C and D represent alternative possibilities but are less directly related to the stated status code.23 / 32
Sarah: 'Hey team, the build failed again! The error message mentions a '403' status code. I'm not sure what that means in this context—should we investigate the authentication setup or something related to permissions? Mark: 'I think it might be a CORS issue.' Which of the following best explains Mark's suggestion?
The '403 Forbidden' HTTP status code specifically indicates that the client does not have permission to access the requested resource. CORS (Cross-Origin Resource Sharing) violations are a frequent cause of this error when JavaScript running from one domain attempts to access resources on another domain. Therefore, Mark is correctly suggesting to investigate whether the build process is attempting to access external resources in a way restricted by CORS policies – a common issue in modern web development.
24 / 32
Mark: 'We're seeing a high latency on the API calls from our mobile app. The monitoring dashboard shows increased response times for requests to the /users endpoint. Initial investigation suggests it might be related to database queries... but I'm not entirely clear on what 'cold cache' means in this context. Should we focus on optimizing the SQL query, or is there something else impacting performance?This question tests understanding of a common performance issue terminology. A 'cold cache' refers to data that hasn't been recently accessed or refreshed in the application server's memory (or a CDN). While optimizing database queries is important for long-term performance, addressing the cold cache – which directly impacts retrieval speed – is the immediate priority when dealing with high latency. Options A and B misinterpret the role of caching; option D incorrectly assumes it's just jargon, and option C highlights the correct prioritization.
25 / 32
Mark: 'We've received a notification from the monitoring system – 'High CPU Utilization' on Server B. The application is reporting intermittent slowdowns during peak hours. We suspect it might be related to our image processing service. I need some clarification on what 'thread pool exhaustion' means in this context; we're currently running with a default size, and I'm wondering if scaling that up would resolve the issue.' Which of the following best describes Mark's concern?Mark is worried about the application's ability to handle concurrent requests. Thread pool exhaustion refers to a situation where the number of threads available in a thread pool exceeds the number of incoming requests, leading to delays and slowdowns as tasks queue up waiting for processing time. The default size of the thread pool likely isn't sufficient to cope with peak loads, causing this issue; scaling it would provide more capacity.
26 / 32
Mark: 'The new deployment is running slowly. The logs show a lot of 'Connection Refused' errors when our frontend tries to access the backend API. I'm not sure if it's something to do with the load balancer configuration or the server itself.' Which of the following options best reflects Mark's concern?A. The database is overloaded and needs scaling.
B. The load balancer isn't correctly routing traffic to the backend servers, potentially due to a misconfiguration.
C. The API code contains inefficient algorithms causing excessive processing time.
D. The application server's CPU resources are being exhausted.
Mark is experiencing 'Connection Refused' errors when accessing the API. This strongly suggests an issue with network connectivity or routing – specifically, the load balancer isn't directing requests to the available backend servers. The other options (database overload, inefficient code, and CPU exhaustion) are potential issues but less directly related to the immediate symptom described in the log message. Therefore, option B is the most accurate reflection of his concern.
27 / 32
During a code review for a new feature that integrates with a third-party payment gateway, Liam comments: 'The response from the API is returning a
A. The authentication token used to access the payment gateway API has expired or been revoked.
B. The third-party payment gateway is experiencing temporary downtime or high traffic volume, leading to service unavailability.
C. There's a bug in our code that's causing excessive requests to be sent to the payment gateway API.
D. The network connection between our application and the payment gateway has been disrupted.
503 Service Unavailable error intermittently. It seems like the external service might be overloaded.' Considering this context, which of the following best explains Liam's concern? A. The authentication token used to access the payment gateway API has expired or been revoked.
B. The third-party payment gateway is experiencing temporary downtime or high traffic volume, leading to service unavailability.
C. There's a bug in our code that's causing excessive requests to be sent to the payment gateway API.
D. The network connection between our application and the payment gateway has been disrupted.
Liam is observing an HTTP status code indicating that the service he's relying on (the third-party payment gateway) is temporarily unable to handle requests. A
503 Service Unavailable error specifically points to resource constraints or downtime on the external server, making option B the most accurate explanation of his concern. Options A, C and D represent alternative possibilities but are less directly related to the stated status code.28 / 32
Sarah: 'Hey team, the build failed again! The error message mentions a '403' status code. I'm not sure what that means in this context—should we investigate the authentication setup or something related to permissions? Mark: 'I think it might be a CORS issue.' Which of the following best explains Mark's suggestion?
The '403 Forbidden' HTTP status code specifically indicates that the client does not have permission to access the requested resource. CORS (Cross-Origin Resource Sharing) violations are a frequent cause of this error when JavaScript running from one domain attempts to access resources on another domain. Therefore, Mark is correctly suggesting to investigate whether the build process is attempting to access external resources in a way restricted by CORS policies – a common issue in modern web development.
29 / 32
Mark: 'We're seeing a high latency on the API calls from our mobile app. The monitoring dashboard shows increased response times for requests to the /users endpoint. Initial investigation suggests it might be related to database queries... but I'm not entirely clear on what 'cold cache' means in this context. Should we focus on optimizing the SQL query, or is there something else impacting performance?This question tests understanding of a common performance issue terminology. A 'cold cache' refers to data that hasn't been recently accessed or refreshed in the application server's memory (or a CDN). While optimizing database queries is important for long-term performance, addressing the cold cache – which directly impacts retrieval speed – is the immediate priority when dealing with high latency. Options A and B misinterpret the role of caching; option D incorrectly assumes it's just jargon, and option C highlights the correct prioritization.
30 / 32
Mark: 'We've received a notification from the monitoring system – 'High CPU Utilization' on Server B. The application is reporting intermittent slowdowns during peak hours. We suspect it might be related to our image processing service. I need some clarification on what 'thread pool exhaustion' means in this context; we're currently running with a default size, and I'm wondering if scaling that up would resolve the issue.' Which of the following best describes Mark's concern?Mark is worried about the application's ability to handle concurrent requests. Thread pool exhaustion refers to a situation where the number of threads available in a thread pool exceeds the number of incoming requests, leading to delays and slowdowns as tasks queue up waiting for processing time. The default size of the thread pool likely isn't sufficient to cope with peak loads, causing this issue; scaling it would provide more capacity.
31 / 32
Mark: 'The new deployment is running slowly. The logs show a lot of 'Connection Refused' errors when our frontend tries to access the backend API. I'm not sure if it's something to do with the load balancer configuration or the server itself.' Which of the following options best reflects Mark's concern?A. The database is overloaded and needs scaling.
B. The load balancer isn't correctly routing traffic to the backend servers, potentially due to a misconfiguration.
C. The API code contains inefficient algorithms causing excessive processing time.
D. The application server's CPU resources are being exhausted.
Mark is experiencing 'Connection Refused' errors when accessing the API. This strongly suggests an issue with network connectivity or routing – specifically, the load balancer isn't directing requests to the available backend servers. The other options (database overload, inefficient code, and CPU exhaustion) are potential issues but less directly related to the immediate symptom described in the log message. Therefore, option B is the most accurate reflection of his concern.
32 / 32
During a code review for a new feature that integrates with a third-party payment gateway, Liam comments: 'The response from the API is returning a
A. The authentication token used to access the payment gateway API has expired or been revoked.
B. The third-party payment gateway is experiencing temporary downtime or high traffic volume, leading to service unavailability.
C. There's a bug in our code that's causing excessive requests to be sent to the payment gateway API.
D. The network connection between our application and the payment gateway has been disrupted.
503 Service Unavailable error intermittently. It seems like the external service might be overloaded.' Considering this context, which of the following best explains Liam's concern? A. The authentication token used to access the payment gateway API has expired or been revoked.
B. The third-party payment gateway is experiencing temporary downtime or high traffic volume, leading to service unavailability.
C. There's a bug in our code that's causing excessive requests to be sent to the payment gateway API.
D. The network connection between our application and the payment gateway has been disrupted.
Liam is observing an HTTP status code indicating that the service he's relying on (the third-party payment gateway) is temporarily unable to handle requests. A
503 Service Unavailable error specifically points to resource constraints or downtime on the external server, making option B the most accurate explanation of his concern. Options A, C and D represent alternative possibilities but are less directly related to the stated status code.Frequently Asked Questions
What will I practice in "Expand the Abbreviation — IT Abbreviations Exercises"?
This is an IT Abbreviations exercise set. It walks through 32 scenario-based multiple-choice questions built around real usage of IT Abbreviations terminology that IT professionals encounter on the job.
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This set contains 32 questions. Each one shows immediate feedback and a detailed explanation after you answer, so you learn the correct usage right away rather than waiting for a final score.
Do I need prior experience to complete this exercise?
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What if I don't understand a term used in a question?
Read the explanation shown after you answer each question — it breaks down the correct term in plain English with a real-world example. You can also check the site Glossary for quick definitions.
How is this different from reading a blog article on the topic?
Exercises like this one are interactive drills that test and reinforce specific vocabulary through multiple-choice questions, while blog articles explain concepts in prose. Practising here after reading builds active recall, not just passive recognition.
Where can I find more IT Abbreviations exercises?
See the IT Abbreviations exercises hub for the full set of related pages, or browse all exercise categories from the main Exercises index.
Can I use this exercise to prepare for a technical interview?
Yes — IT Abbreviations vocabulary comes up often in technical discussions and interviews. Pair this exercise with our dedicated Interview Preparation section for role-specific practice.