When selected the “Group” function will keep the selected objects’ original properties and make them into a new object, and this new group, as the same as other object, can be selected, copied, pasted and set object properties.
“Ungroup” will turn the object which has just been grouped into previous situation. The object which has just been grouped by more than 1000 objects will become 10 objects. If the object is a vector file which has different pen color, it will become some objects according to color.
The shortcut keys of “Group” and “UnGroup” respectively are: Ctrl+G and Ctrl+U.