A tray icon has a distinct lifecycle:
Under the hood, the tray icon is not just a static image; it is a complex interaction between the application and the Operating System’s Shell.
As applications move to the web, the definition of "background process" changes. PWAs can now register tray icons, blurring the line between a website and a native utility. This allows a website for email or music to run in the background, receiving notifications just like a native Windows app.
Unlike standard windows or taskbar buttons, tray icons represent applications that are:
The design of a tray icon follows a specific psychological contract with the user: