What HTTP methods exist?

Main HTTP methods:

• GET — request to retrieve data from the server. Should not change the state.
• POST — send data to the server to create a resource or perform an operation.
• PUT — update an existing resource or create it if it does not exist.
• DELETE — delete a resource.
• PATCH — partially update a resource.
• HEAD — retrieve only response headers, without the body.
• OPTIONS — request supported server methods for a resource.

Each method has its purpose and semantics, which are important for proper REST API construction and testing.