What HTTP methods exist?

There are main HTTP methods that define the action the client wants to perform on a resource:

• GET — retrieve data from the server.
• POST — send data to the server, usually to create a resource.
• PUT — completely replace a resource on the server.
• PATCH — partially update a resource.
• DELETE — delete a resource.
• HEAD — get only the response headers, without the body.
• OPTIONS — find out which methods the server supports for a resource.
• TRACE — perform a diagnostic test request.

These methods are standardized and used for building RESTful APIs and client-server interactions.