You can dock, anchor, float, or merge any window in the Microsoft Office Visio drawing environment.
Docked windows
You can dock windows to the edge of the program window, to have them stationary but ouside of the drawing window. For example, when you open a template, its Shapes window is docked.

The Custom Properties window docked to the program window.
Anchored windows
You can anchor windows to an edge inside the drawing window. To save space, you can have anchored windows hide automatically when you're not using them.
Tip
To have a window hide automatically, click the
AutoHide button

.

The Custom Properties window anchored to the edge of the drawing window.
Floating windows
You can float windows to move them anywhere inside the drawing page. (If you move them close to the edge of the page, they might dock or anchor.)

The Custom Properties window floating in the drawing window.
Merged windows
You can merge the Pan & Zoom, Custom Properties, Size & Position, and Drawing Explorer windows. When you merge windows, they occupy the same space. At the bottom of the window, page tabs appear with which you can switch from one to the other. You can also merge shape windows, which show stacked title bars instead of tabs.
Tip
To merge windows, drag one window on top of the other until the tab appears at the bottom of the window.

Merged windows