When to Use Appdata?
If a Program Wants to Have a Single Set of Settings or Files to Be Used by Multiple Users, Then It Should Use the Programdata Folder – but If It Wants to Store...
If a program wants to have a single set of settings or files to be used by multiple users, then it should use the ProgramData folder – but if it wants to store separate folders for each user, programs should use the AppData folder.
What is the AppData folder used for?
The AppData folder includes application settings, files, and data unique to the applications on your Windows PC. The folder is hidden by default in Windows File Explorer and has three hidden sub-folders: Local, LocalLow, and Roaming. You won't use this folder very often, but this is where your important files reside.
Do I need to keep AppData?
By backing up the AppData folder, it ensures you can easily restore a program's settings or restore your profiles from a backup. It is recommended to backup your entire user account directory, including the hidden AppData directory.