Primatte contributes to a process called 'chromakey'. But what exactly is chromakey? Knowing will help you to determine whether Primatte is right for your photography work.
Chromakey is the process used to insert a new background behind a model or object. The subject is photographed against a background of a single color (or a relatively narrow range of colors). Then that single color is removed digitally. Primatte performs this extraction directly inside Photoshop as a plugin.
Digital Anarchy Primatte Chromakey v2.1 for Adobe Photoshop