Answer
4 Components of a REST API
1. API Client
The software or application that initiates requests to the API server to retrieve or manipulate data.
- ✓Acts as intermediary between the end-user and the API server
- ✓Responsible for sending properly formatted requests and handling responses
Example: A mobile app that displays weather information. The app sends a request to the weather API server to fetch current weather data.
2. API Request
A message sent by the client to the API server, indicating the action it wants to perform.
Contains:
- ✓Endpoint (URL) — specific API resource path
- ✓HTTP Method — GET, POST, PUT, DELETE, etc.
- ✓Headers — metadata like Content-Type, Authorization
- ✓Body — data payload (for POST/PUT requests)
Example: GET https://api.weather.com/current-weather — fetches weather data for a location.
3. API Server
A software application that receives requests, processes them, interacts with the database or other services, and generates a response.
- ✓Acts as the gateway to the backend system
- ✓Provides access to the requested resources
Example: The weather API server receives the GET request, queries its database, and generates a response with temperature, humidity, and weather conditions.
4. API Response
The message sent by the server back to the client in reply to the API request.
Contains:
- ✓Data requested by the client (JSON/XML)
- ✓Status codes — 200, 201, 404, 500, etc.
- ✓Headers — Content-Type, Cache-Control, etc.
Example: After processing the GET request, the weather server sends back { "temperature": 25, "humidity": 65, "condition": "Sunny" }.