The taskbar will also show the icon of the app for any window you have open. If you like, you can pin an app to the taskbar to always show the app’s icon on the taskbar whether the app is open or not. Pinning an app to the taskbar makes it easier to open the app on demand from the taskbar.
Items you pin to the taskbar are stored and referenced in both locations below for your account.
In the registry:
In a folder:
%AppData%\Microsoft\Internet Explorer\Quick Launch\User Pinned\TaskBar
This tutorial will show you how to back up and restore all pinned items on your taskbar in Windows 10 and Windows 11.