Glossary

The terms used across this site, in plain language. Where a term has its own page, the name links to it.

API and HTTP

Term	Meaning
API	The agreed way for one program to ask another for something. See What is an API?
API client	A tool for sending requests and inspecting responses, such as ApiWorkbench
Body	The data carried by a request or a response
Client	The program that sends a request
Content-Type	The header that says what format a body is in
Cookie	A small value a server asks the client to keep and send back
CORS	Rules browsers apply before letting a web page call an API on another address
cURL	A command-line program for sending requests. Many API docs show examples as curl commands
Endpoint	One address an API answers at, such as GET /users/42
GraphQL	A style of API where the client sends a query describing exactly the data it wants
gRPC	A fast, strongly typed way for services to call each other, described in .proto files
Header	A Name: value line carrying information about a request or response
HTTP	The rules requests and responses follow on the web. See HTTP basics
HTTPS	HTTP over an encrypted connection
Idempotent	Giving the same result whether sent once or many times. GET, PUT and DELETE should be
JSON	The text data format most APIs use. See JSON basics
localhost	"This computer". http://localhost:4010 is port 4010 on your own machine
Method	The verb of a request: GET, POST, PUT, PATCH, DELETE and others
OpenAPI	A standard file format describing an API's endpoints. Formerly called Swagger
Path parameter	A changeable part of a path, such as the 42 in /users/42
Payload	Another word for the body
Port	The number after the colon in an address. It selects one program on a computer
Query parameter	A name=value option after the ? in a URL
Request	What the client sends: method, URL, headers and an optional body
Response	What the server sends back: status, headers and an optional body
REST	The common style of API built on HTTP methods and URLs that name things
Server	The program that receives requests and answers them
Status code	The three-digit result of a request, such as 200 or 404
URL	The full address of an endpoint
Webhook	A request a service sends to you when something happens
WebSocket	A connection that stays open so both sides can send messages at any time

Signing in

Term	Meaning
API key	A secret string that identifies an application
Authentication	Proving who you are. Failure is a 401
Authorization	Being allowed to do something. Failure is a 403
Basic auth	A username and password sent Base64-encoded in a header
Bearer token	A string that stands for a signed-in user, sent with each request
JWT	A common token format: three dot-separated pieces, signed but readable
OAuth 2.0	A procedure for getting a token without sharing a password
Scope	A permission attached to a token
Mutual TLS	The client proves its identity with a certificate, as the server does

See How APIs know who you are.

ApiWorkbench

Term	Meaning
Capture	A rule that saves a value from a response into a variable. See Captures
Collection	A named set of saved requests, with folders. See Collections
Collection runner	Runs a collection's requests in order and reports passes and failures. See Collection runner
Console	A log of every request actually sent, plus script output
Data file	A CSV or JSON file whose rows feed a run, one row per iteration
Dynamic variable	A built-in placeholder such as {{$guid}} that produces a fresh value on every send
Environment	A named set of variables, such as Local or Staging. Switching it re-points every request
Iteration	One pass through the requests in a run
Script	JavaScript that runs before a request or after its response
Test	A check on a response, run after every send. See Tests without code
Variable	A named value written as {{name}} and filled in when the request is sent
Workspace export	A file holding your collections and environments, for sharing or backup

Mock Studio

Term	Meaning
Fault	A deliberate failure: a dropped connection, an empty or broken body, or no answer at all
Flow	A scripted journey of several requests, run by many virtual users at once
Latency	Delay added before a response
Mock server	A stand-in API that returns designed responses. See Your first mock server
Path template	A path with changeable parts: /users/:id, /files/*, /assets/**
Project	One mock API: its endpoints, port and settings, saved as one JSON file
Proxy	Forwarding requests the mock does not handle to a real API
Recording	Turning proxied real responses into mock endpoints
Response strategy	How an endpoint picks an answer: single, conditional rules, sequence or random
Rule	A condition on the request that selects a response
Template token	A {{…}} placeholder filled in per request, such as {{params.id}} or {{uuid}}
Tunnel	A public internet address that forwards to the mock on your computer

Networking and SSH

Term	Meaning
DHCP	How a router hands out addresses to devices on its network
DNS	Turns names such as learn.dhivalabs.com into IP addresses
Firewall	Decides which network connections a device accepts
Host key	The key that proves an SSH server's identity. Check its fingerprint on the first connection
IP address	A device's address on a network, such as 192.168.1.20
LAN	Your local network: the devices on the same Wi-Fi or switch
NAT	How many devices share one public address through a router
Port forwarding	Carrying a connection through an SSH session, or opening a router port to the internet
Private address	An address that only works inside one network: 192.168.x.x, 10.x.x.x, 172.16.x.x to 172.31.x.x
SFTP	File transfer over an SSH connection
SSH	An encrypted way to use another computer's shell, copy files and forward ports
SSH key pair	A private key you keep and a public key you put on servers, used instead of a password

See the Networking and SSH track.

Git

Term	Meaning
Branch	A movable name for a line of commits
Commit	A saved snapshot of the project, with a message and an author
Conflict	Two changes to the same lines that Git cannot combine by itself
Merge	Joining the history of two branches
Rebase	Replaying commits on top of another starting point
Remote	Another copy of the repository, such as one on GitHub, usually called origin
Repository	A project folder whose history Git tracks
Staging area	The changes chosen for the next commit

See the Git track.

Databases

Term	Meaning
Foreign key	A column that points at a row in another table
Index	A lookup structure that makes finding rows faster
Primary key	The column that identifies each row uniquely
SQL	The language for asking relational databases questions and changing their data
Table	Rows of the same kind of thing, with named columns
Transaction	A group of changes that succeed together or not at all

See the Databases track.

Android

Term	Meaning
ADB	Android Debug Bridge: the tool for talking to a phone from a computer
APK	An Android app package file
Developer options	Hidden Android settings that include USB debugging
Logcat	Android's running log of messages from the system and apps
USB debugging	Lets a computer you authorise control the phone through ADB

See the Android and ADB track.

AI

Term	Meaning
Context window	How much text a model can take into account at once
Embedding	A list of numbers representing a piece of text, so similar texts can be found
Hallucination	A fluent, confident answer that is wrong
LLM	Large language model: a model that generates text by predicting what comes next
MCP	Model Context Protocol: a standard way for AI apps to call tools
RAG	Retrieval-augmented generation: finding relevant passages first, then answering from them
Token	A piece of a word: the unit models read, write and count

See the AI and local models track.

Testing

Term	Meaning
Assertion	A single check that must be true, such as "status equals 200"
Boundary test	Testing at the edges of what is allowed: the largest valid value, and one more
Contract	The agreed shape of an API: its endpoints, fields, types and status codes
Data-driven test	One request run many times with different inputs from a table
End-to-end test	A test that follows a whole user journey through several requests
Functional test	Does the endpoint do what it should for a valid request?
Happy path	The case where everything is valid and everything works
Load test	Many requests at once, to see how speed and errors change under pressure
Negative test	Sending something wrong on purpose, to check it is refused properly
p50, p95, p99	Percentiles of response time. p95 = 300 ms means 95 in 100 requests finished within 300 ms
Ramp-up	Starting virtual users gradually instead of all at once
Regression test	Re-running old tests to check that a change broke nothing
Resilience test	How a client behaves when the API is slow, failing or down
Smoke test	A few quick checks that the system is alive at all
Test case	One scenario: the input, the steps and the expected result
Test plan	What will be tested, how, and what counts as done
Think time	A pause between a virtual user's steps, imitating a person
Throughput	Requests handled per second
Virtual user	One simulated client in a load test

See the testing guides.