Use groups to organize your graphics or to add extra transform spaces.
Activate the Group tool with the G shortcut. Click anywhere in an artboard to add a new group. Now drag and drop objects into the group in the Hierarchy.
You can also wrap a selection of shapes into a group with ⌘+G in macOS or Ctrl+G in Windows.
Unwrap a group with ⌘+Shift+G in macOS or Ctrl+Shift +G in Windows.
Group Style
The Style property of a group can be set to Group or Target.
The Target option draws a different icon on the Stage that is always visible, regardless of whether the group has children (usually a group only displays an icon if it is empty). When a group displays as a Target, it also disables the functionality described in Selecting and Navigating Groups section. This means you can immediately click through to any child of the group (no need to double-click, enter/esc, or Deep Select).
The Target option is particularly useful when working with Constraints.