The management console is a web application that gives you the control you need to manage your web client environment. You can manage users, sessions, initiate session logging, and manage application tenant configuration through the Session Manager and Tenant Manager. The extensible snap in model of the console also gives ISVs and application developers the opportunity to create custom snap ins to give you even more control of your web client environment.
In other words, you can see who is logged in, how long they have been in, what company/tenant they are using. You can also kick them out if you want.
Here's what it looks like: