Author's note: the Context section of this page would benefit from screenshots. During the presentation, I was able to demo the options, but obviously that doesn't work as well with static docs. I'll add them myself in time, unless someone beats me to it. End Note
Blocks and Menus
Every time you create a menu, a corresponding block is created that displays that menu.
You can also create custom blocks at admin/structure/block/add.
Now that we have these blocks, we need to display them.
The two commonly used methods of controlling block display are the core block display functionality, or the contributed Context module. Both means achieve the same goal; the context module provides more flexibility.
Core Block display
The core block visibility settings can be accessed at admin/structure/block.
To display a block in a region, use the drop down menu for the block you want to show:
In addition to setting the region for a block, you can also set additional features by using the "configure" link visible in the above screenshot.