Marketplace Workflow Triggers & Actions are the custom workflow triggers & actions managed in App Marketplace. The App Marketplace is a directory of Apps with Custom Workflow Triggers/Actions, Custom Providers, etc,. that you can install and use in your account.

App Marketplace

Note: If 'App marketplace' is not visible on your account, you can enable it from the labs or reach your admin.
To use the Custom Triggers and Actions linked to the app in the workflows, you must install the corresponding app on your account.