API
Here’s a clean study table you can add to your guide.
| REST Method | Purpose | Description | Common Usage Example |
|---|---|---|---|
| GET | Retrieve data | Used to request or fetch information from a server or API. Does not modify data. | Retrieve customer profile, chat history, ticket status |
| POST | Create / Send data | Used to submit new data to a server or trigger actions. Often creates new resources. | Start chat session, create ticket, authenticate user |
| PUT | Update existing data | Used to fully update or replace an existing resource. | Update customer information, modify interaction settings |
| PATCH | Partial update | Used to update only specific fields of an existing resource. | Change customer status, update phone number only |
| DELETE | Remove data | Used to delete a resource or remove information from the system. | Delete session, remove user, close/delete record |
| OPTIONS | Discover supported methods | Used to determine what operations an API endpoint supports. Often used in CORS/preflight checks. | Browser checking allowed API methods |
| HEAD | Retrieve headers only | Similar to GET but returns headers only, without response body. Useful for validation or testing. | Check if resource exists, validate API availability |
Example REST API Calls
GET Example
GET /api/customers/12345
Purpose: Retrieve customer information.
POST Example
POST /api/chat/start
Purpose: Create/start a new chat session.
PUT Example
PUT /api/customer/12345
Purpose: Update full customer record.
PATCH Example
PATCH /api/customer/12345
Purpose: Update only selected fields.
DELETE Example
DELETE /api/session/12345
Purpose: Delete session or resource.
Easy Interview Explanation
REST APIs
REST APIs allow systems to communicate using standard HTTP methods such as GET, POST, PUT, and DELETE to retrieve, create, update, or remove data.