Blocks and Regions

The placement of blocks is defined by your theme, and to see the how they will display, Drupal has a nice utility.

If you are having issues visualizing your blocks and how they display on the region go to your blocks page at: admin/structure/block

Near the top of the blocks page, there is a link to demonstrate block regions (THEME).  Click that link.

Demonstrate Block Regions
The red arrow shows the location of the Demonstrate block regions link

This link will take you to: admin/structure/block/demo/THEME.  From this page you will see highlighted regions.

Demonstrate Block Regions Example
This is the business theme, which is used in this site.  The yellow areas are the regions.

 This is a great way to see regions visualized!

If for some reason, you do not have the demonstrate block regions link, you need to ensure that you have the system help block enabled.  Also ensure the admin theme, usually the Seven theme, is enabled.