Select an object
When you left-click on an object, the previous selection is deselected.
This adds an object to the current selection if it was not selected, otherwise removes the object from the current selection.
Edit the object
This switches to the object’s most natural editing tool (the Node tool for paths, a corresponding shape tool for shapes, and the Text tool for text). For groups, double-clicking performs the Enter group command (the group becomes a temporary layer, 4.6.1 Layer Hierarchy). Double-clicking in empty space switches to the parent layer ...