Tabs in gedit can be moved, making it easier to work with your files. Tabs can be can re-ordered within the same window, moved outside of gedit (creating a new gedit window), and moved from one window to another.
To change the ordering of tabs in a window:
Click and hold the mouse button on the tab
Move the tab to the desired position among the other tabs
Release the mouse button
The tab will be placed in the position closest to where you release the tab, immediately beside other opened tabs.
To drag a tab into a new window:
Click and hold the mouse button on the tab.
Drag the tab out of the gedit window.
Release the mouse button.
or, while the tab to be moved is open, choose Documents ▸ Move to New Window
To move a tab into a new window when gedit is maximized, drag the tab onto the top bar at the top of the screen.
If you want to move a tab from one window to another:
Click and hold the mouse button on the tab
Drag the tab to the new window
Place it beside other tabs in the new window
Release the mouse button
See gedit-shortcut-keys#gedit-tab-shortcuts for shortcuts to make it easier to manage your tabs.