APEX REST callouts are a powerful feature in Salesforce that allows developers to integrate external systems and data sources with their Salesforce orgs. With APEX REST callouts, you can make HTTP requests to external APIs and retrieve data in real time, which can be used to update records, trigger workflows, and perform other actions in your Salesforce org.
APEX REST callouts use the HTTP protocol to communicate with external systems, and they can be used to interact with a wide range of data sources, including REST APIs and custom web services. To make an APEX REST callout, you'll need to write a class that encapsulates the HTTP request and response logic and then call that class from your main APEX code.