What does the @HttpGet annotation do in Salesforce?

The @HttpGet annotation in Salesforce is specifically designed to handle HTTP GET requests, which are typically used to retrieve data from a server. By using this annotation in your Apex class, you are creating a method that responds to incoming GET requests, allowing you to read or retrieve records from the Salesforce database or external services.

In the context of RESTful services, the GET method is intended for fetching information, such as querying a list of records or obtaining the details of a single record. This aligns perfectly with the way the @HttpGet annotation is utilized within Salesforce, serving the purpose of data retrieval without modifying the underlying data.

Thus, when the @HttpGet annotation is used, it signifies an action that is primarily focused on reading or retrieving records, making this the correct choice.