You can order your content display by using blocks, choosing to show or hide the blocks on content types, nodes, themes,.. This can lead to complex situations..
This module controls the blocks from the 'context' of what you see.
An example. Looking at a node of the basic content type is see a normal menu in the main navigation block.
Looking at a node form the 'article' content type i put the main menu in the left sidebar.
Go to Context and add a rule, starting with a condition.
I choose node bundle.
Than add a reaction.
Give the block a place.
Do this also for the other content type..
Context is being used in complex layouts. You keep control..