In an HTTP callout, what are the two minimum pieces of information required?

In an HTTP callout, the two essential pieces of information required are the endpoint URL and the HTTP method. The endpoint URL specifies the location of the resource that the callout will interact with, and the HTTP method indicates what action should be performed on that resource—such as retrieving data (GET), sending data (POST), updating data (PUT), or deleting data (DELETE).

Having the endpoint URL is crucial because it directs the callout to the correct service or application that is expected to handle the request. The HTTP method is equally important since it defines the type of operation to be carried out on the specified resource.

For effective communication between systems, a valid combination of both the endpoint URL and HTTP method is mandatory, as these determine the functional scope and behavior of the callout.