Channels are used within Projects for grouping tests for a particular method of communication, such as Inbound Calls or Outbound Calls or Website Chats.
Create a new Channel for each method of communication that you want to create Tests for.
You can also use Channels to group sets of tests together so that you can run them easily in a group. For example, you can have multiple Channels that connect to the same phone number (use the Clone Channel function to do this easily). and put groups of tests (like FAQ, appointment scheduling, and regression tests) in each channel that you can run as a batch with the "Run All Tests" button.