For HTTP request actions, templates describe the HTTP request. You can use variables that replace values in the URL path and payload when the HTTP request is sent.
For emails, you can use a template with variables to replace values in the body of the message.
You can configure custom variables if you need something beyond the predefined ones. This article provides examples of how you can use different Apache Velocity Template variables in HTTP request action and email templates.
The table below describes widely used Velocity variables to help you become more familiar with Velocity when you are customizing templates. A variable consists of a leading “$” followed by an identifier. It should look like this: $foo