Docking Feature (Side Tabs)
To move a block (quickmail, calendar, etc.) to the clickable docking area at the far left side of the course page, click the small rectangles at the upper right of any block. This converts the block into a tab on the side of your browser that expands when you click or mouse over. You can undock a block when you want to see it on the main page again.
The video below illustrates how to use this feature: