Display mirroring

Display mirroring makes two or more displays show the same desktop. In an extended desktop, each display gives you a different area for your windows; in a mirrored arrangement, the displays share the desktop image.

BetterDisplay describes this relationship using a source and a target. The source supplies the desktop being mirrored. The target shows that image, with its settings affecting how the image is presented. Keeping those roles in mind makes the direction of a mirroring command easier to follow.

Mirroring is different from displaying a captured stream in a window or full-screen overlay. A virtual screen can supply a desktop for either arrangement, but the connection, resolution and permission requirements differ.

See Resolution and Picture in Picture for those related concepts. Mirror Display / Mirror Virtual Screen explains the mirroring options.