The Workbench allows you to have multiple files open in multiple editors. Unlike views, editors cannot be dragged outside the Workbench to create new windows. However, you can tile editor sessions within the editor area, in order to view source files side by side.
This is a similar operation to moving and docking views inside the Workbench, except that all editor sessions must be contained within the editor area.
Opening files for editing
Changing the placement of the tabs