What are Blocks?
Blocks in Moodle are items which may be added to the left, right, or center column of any page. They may also be added to the center of the My Home (My Moodle) page. Additionally, you may theme the position of blocks in the center of a page as well.
Any Block can be made "Sticky" so that it appears in all the contexts below, such as throughout a course or a particular activity. Visit the MoodleDoc's Block Settings page to find out more about Block Settings.
Blocks can be placed on the side of the screen (if your theme supports it) via the Dock icons (Block to Dock and Dock to Block );