As per Zendesk:
A macro is a prepared response or action that an agent can manually apply when they are creating or updating tickets. Macros contain actions that can update ticket properties.
Unlike triggers and automations, macros only contain actions, not conditions. Conditions aren't used because nothing is automatically evaluating tickets to determine if a macro should be applied. Agents evaluate tickets and apply macros manually as needed.
Macros can do a wide range of these things, but the most common actions are:
Instead of managing Zendesk macros via Zendesk itself, we instead use GitLab itself via the zendesk-macros project. This allows us to have version-controlled macros. For more information on managing Zendesk via the various GitLab projects, please review Using the sync repos.
As we have many macros, and they change quite frequently, the best resource to see all the current macros would be the zendesk-macros project.