When you create a drawing with many objects, it is useful to group objects together to help organize your drawing. Grouping makes it easier to select objects, and makes it possible to manipulate several objects at once.
Group objects when you want to create a collection of individual objects. Grouping does not change an object's appearance.
Changing a style of an object group changes all objects in the group to the new style. For example, if you select a group of objects and change the interior fill color to red, all objects in the group become red unless you have Smart Colorization of Groups selected. (See Smart Colorization for more information.)