Backbone render return this

I'm trying to figure out some of the 'patterns' to set up a Backbone-project. In the examples below, in the 'render'-function, the author returns an instance of 'this'.

Why is this? Is it specific for the example, or something common for Backbone? I don't see why one should return 'this' in the 'render'-function.

The examples

http://backbonefu.com/2011/08/filtering-a-collection-in-backbone-js/

Calling a jQuery plugin in a Backbone render method