Functionality is added via Plugins. They contain pre-built Functions, Types and Services. Think of them as Nuget or npm packages that can be installed and used in your Linx Solution.
The Linx and Utilities plugins are installed by default and contain all the basic types and functions. Click on the ADD PLUGINS button to see all available plugins.
Plugins contain simple types like string or integer, generic functions like CallRESTService, complex services like RESTHost and specialized functionality like the AWS APIs.