What are IIS web server Dynamic Restriction Settings?

In the IIS Manager, under a web site's "IP Address and Domain Restrictions", there's an option called "Edit Dynamic Restriction Settings". What does this mean, and what kind of features are available?

Basically, you can limit traffic in two ways: the number of concurrent operations from any given IP address (default: 5) and the number of requests in any given time amount (default: 20 requests in 200 milliseconds).

A third option allows you to only log these situations, instead of automatically blocking them.

There's a nice IIS blog post about this feature, be sure to check it out.