What is the difference between HTTP request methods?

The main difference between HTTP request methods lies in their semantics and purpose:

• GET: Requests a representation of the specified resource. Data is transmitted in the URL. Used for retrieving data and should have no side effects (be idempotent and safe).
• POST: Sends data to be processed by a specific resource. Used for creating or updating resources. Data is transmitted in the request body. Not idempotent and not safe.
• PUT: Replaces all current representations of the target resource with the request payload. Used for updating or creating a resource if it does not exist. Idempotent but not safe.
• DELETE: Deletes the specified resource. Idempotent but not safe.
• PATCH: Applies partial modifications to a resource. Used for partial updates. Not idempotent and not safe.
• HEAD: Identical to GET but without the response body. Used to obtain metadata about the resource (e.g., headers). Idempotent and safe.
• OPTIONS: Describes the communication options for the target resource. Allows the client to determine which HTTP methods or other parameters the server supports for a specific URL.
• CONNECT: Establishes a tunnel to the resource identified by name. Usually used for SSL/TLS tunneling through an existing proxy.
• TRACE: Performs a diagnostic trace of the path to the target resource. The client can get a copy of its request along the request path. Used for debugging.

Here is a comparative table:

Method	Purpose	Idempotent	Safe	Data Transmission
GET	Retrieve resource	Yes	Yes	URL
POST	Create/update	No	No	Request body
PUT	Full update	Yes	No	Request body
DELETE	Delete resource	Yes	No	URL
PATCH	Partial update	No	No	Request body
HEAD	Get metadata	Yes	Yes	URL
OPTIONS	Describe communication options	Yes	Yes	None
CONNECT	Establish tunnel	No	No	None
TRACE	Trace back request path	Yes	Yes	None