Backlog

Purpose

Store tasks you want to do someday but aren't sure exactly when. Think of it as your "someday" list.

There are three ways to open and view the backlog:

From the right hand panel, click on the "Filebox" icon.
Use the keyboard shortcut Shift + B to toggle the backlog into view in the right hand panel
Use the command palette to search for and toggle the backlog into view.

There are three ways to move a task into the backlog:

You can filter the backlog to only show tasks in a certain channel or context by selecting that context or channel.
Click the "Search" button in the top right hand corner to search items in your backlog

If you have tasks that often roll over from day to day, move them to your backlog.
The backlog is not a replacement for a project management tool. It can be useful for small one off items but isn't designed to handle complex workflows better suited to a project management tool that can be integrated with Sunsama.
If you worry about things getting forgotten in your backlog: create a weekly recurring task called "Review Backlog" to remind you to review and groom your backlog.
There's no officially supported feature for task templates but here's how you can workaround it. Create a task in your backlog and putting it under a "Templates" Channel. That way you can always see all your templates in one place, then when you are ready to use it, click into the task, click the "..." menu, then click "Duplicate".
If you have a task in the backlog and then work on it today by either running the timer on the task or by placing time for it on the calendar, then that task will move out of the backlog and into today's column or whatever day you scheduled time to work on it.