1.1 HTTP METHODS

HTTP methods (or verbs) are used to perform operations on resources identified by a URI. Each method has a specific purpose.

Main HTTP Methods Reference

Method	Purpose	Idempotent (Same result if called multiple times)	Safe (No server side changes)	Example	Typical Use
GET (Read)	Retrieve data from the server.	Yes	Yes	GET /users GET /users/10	* Get all users * Get user by id
POST (Create)	Create a new resource.	No	No	POST /users	* Create a new user * Submit form data
PUT (Update)	Update or replace an existing resource entirely.	Yes	No	PUT /users/10	* Update user (full) * Replace user info
PATCH (Partial Update)	Partially update an existing resource.	Yes	No	PATCH /users/10	* Update user (partial) * Change single field
DELETE (Delete)	Delete a resource from the server.	Yes	No	DELETE /users/10	* Delete user * Remove resource
OPTIONS (Info)	Get information about supported methods.	Yes	Yes	OPTIONS /users	* Get allowed methods * CORS preflight
HEAD (Partial Headers)	Similar to GET but returns headers only (no body).	Yes	Yes	HEAD /users/10	* Check resource existence * Get metadata

Key Properties

Idempotent Methods

• GET, PUT, DELETE, HEAD, OPTIONS are idempotent.
• Calling them multiple times produces the same result without additional side effects.

Example: PUT /users/10 with same data 5 times results in the same user data.

Safe Methods

Methods that do not change the state on the server.

Safe Methods: GET, HEAD, OPTIONS

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Quick Comparison Matrix

Method	Create	Read	Update	Delete	Idempotent	Safe
GET	–	✓	–	–	✓	✓
POST	✓	–	–	–	❌	❌
PUT	–	–	✓	–	✓	❌
PATCH	–	–	✓	–	✓	❌
DELETE	–	–	–	✓	✓	❌
OPTIONS	–	–	–	–	✓	✓
HEAD	–	✓	–	–	✓	✓

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Interview Tip

• Use the correct HTTP method for the operation.
• GET should not change data.
• PUT replaces the entire resource, PATCH updates partially.

Resource

https://www.rfc-editor.org/info/rfc9110/#section-9