Sections are great. They're a way to partition off part of the content of a text document and treat it differently.

Quick Overview of Sections

Select your text that you want treated differently, choose Insert > Section, and choose any of the options in this window and the tabs such as Columns, Background, etc.

When you insert a section, it just means the content you selected is now partitioned off and assigned the attributes you specified in the Insert Section window.

This section below is in two columns with a gray background, because I used the Columns and Background tabs to apply those settings.

Read More Here.