Custom webapp to integrate with Alfresco Activiti

Hello,

We are exploring usage of Alfresco Activiti BPM Suite to integrate with custom web application.

Documents will be stored in Alfresco using Alfresco integrated Activiti API.

I am a bit confused with REST API to be used for the same.

Please let me know if using following documentation is the proper link?
https://docs.alfresco.com/activiti/docs/dev-guide/1.4.0/#_alfresco_activiti_bpm_suite_api

Is Alfresco Activiti REST API are WebScripts?

Thanks in advance for guiding.