In Moodle, your Grades are accessible via the Navigation block, and courses are most easily viewed via the "Current Course List" module on the right-hand side of the main Moodle page. Occasionally, students will accidentally "dock a block," which means that the block is shown in a minimized form at the top-left corner of the screen (called the "dock").
You can move one of the functional blocks to the dock ("dock the block") intentionally to make that block still available to you, while reducing the amount of space the block takes up on the screen:
When a block is "docked,", it appears as a tab in the left corner of your screen. For example, in the screen capture below, we have docked the Navigation block:
To see the full functionality of a docked block, you need to hover your mouse over the block to expand its content:
More often, a block is docked accidentally. To "undock" the block, click on the > icon that appears in the top-right corner of the expanded block:
The block will then return to its normal location on the right-hand side of the Moodle page.