A group is a series of more than one scene to be viewed in a sequence.  Group scenes together by dragging and dropping one on top of the other.  Groups can be used to show groups of scenes or to leave them out of the video.  

There are two types of groups:

1) A sequence where all scenes will be displayed once their conditions are met

2) Alternative Scenes where the first scene to meet its conditions will be the only scene to be displayed  

Groups are created for the purpose of creating 'Group  Logic'.  Please see the next tutorial on Group Logic for more information.    

Watch this video for a detailed explanation of how to create groups: