Blocks are chunks of content that can be placed on individual or multiple pages. Examples of blocks are:

• Custom word marks or logos replacing Drupal's default site title at the upper left of each page.
• Additional footer content to the right of the main MIT logo and descriptor at the lower left of each page.
• Directives such as "Share this page" that might appear at the bottom of the main content of every page (or specific pages).
• Sidebar content that you wish to display on multiple pages.

Blocks are created and managed in the Structure > Blocks admin panel. Once created, a block must be designated to appear in one of Drupal's page areas. Further details can be adjusted by specifying on which pages the block should display (all pages, all pages except X, only X).