What is the primary function of the HTTP GET method?

The primary function of the HTTP GET method is to retrieve data identified by a URL. When a client sends an HTTP GET request, it asks the server to provide specific data associated with the resource pointed to by the URL. This method does not change the state of the server and is intended solely for retrieving information.

GET requests are generally used to fetch documents, images, or any other type of resource from the server. Importantly, since GET requests should not have side effects on the server, they are considered safe and idempotent, meaning that repeating the request will not alter the server's state.

In relation to the other choices, creating data on the server, deleting resources, or updating existing resources are operations associated with different HTTP methods: POST, DELETE, and PUT/PATCH, respectively. These methods are designed specifically for modifying the server's state, which is not the purpose of a GET request.