What can be transmitted in a GET request?

In a GET request, data can only be transmitted via the URL, usually in the form of query parameters. These are key-value pairs added after the question mark (?) in the URL. For example:

https://example.com/api/items?category=books&sort=price_asc

In a GET request, the request body cannot be transmitted, so all data must be included in the URL. This is typically used for filtering, sorting, pagination, and other parameters that do not change the server state.