What is the function of the OPTIONS HTTP method?

The OPTIONS HTTP method is specifically designed to describe the communication options available for a particular resource. When a client sends an OPTIONS request to a server, the server responds with the allowed HTTP methods that can be used on that resource, as well as any other relevant information regarding the communication options like supported protocols, headers, or methods.

This is particularly useful for developers and web applications that need to understand what actions they can perform on a resource. It helps ensure that clients can communicate efficiently with the server and abide by the appropriate methods and techniques permitted for that resource. By using the OPTIONS method, developers can implement features such as pre-flight requests in CORS (Cross-Origin Resource Sharing), where the client checks before executing potentially unsafe methods on a resource from a different origin. This enhances the security and flexibility of web applications.