If you open the run box on Windows 10 and paste %AppData% in it, or if you open File Explorer and paste the same thing in the location bar, it will take you to a folder named AppData. This folder is present in very single user profile folder configured on a Windows 10 PC. Inside it there are always three folders; Local, LocalLow, and Roaming. These folder names don’t give much away but inside, you will find folders for the various apps you run on your system.
These folders are definitely not where the apps are installed. They install in the Program Files folder in your Windows drive so you might wonder what they’re for.
Local, LocalLow, And Roaming Folders
To start off know that these folders are all created by Windows itself. Even if you only have stock apps installed on your system, opening the AppData folder will reveal these three folders under it. The sub-folders that they contain all depend on the apps you install. Chrome, for example, will add a Google folder under Roaming whereas iTunes will add an Apple folder under Local. The apps you install decide for themselves where they will create their folders but each one has its own purpose.
Remember that these folders exist under your Windows user profile. The apps that create folders under Local, and save data here mean for them to never leave your system. If you were to export your user profile, the apps and the data stored under Local wouldn’t go with it.
LocalLow is the same as Local however, the apps that save data here do so because they do not have access rights to save data to Local or because the data is of such nature that files for it should not be saved to Local or Roaming. If you use portable apps, they may create folders here if they do not create them under Local. Adobe saves files to this folder as well as to the other two folders.
All folders in this folder can be synced to a server and can be copied between PCs to move your user profile. The apps that create folders and save files here, such as Chrome, do so because they need to sync it across a web service or because the data they create is of the nature that it can be synced. Chrome saves your user profile here, among other things.
An app can create folders in all three of these folders and it will save different files to each one. Adobe is an example of this but Microsoft also creates and saves a few Windows files to each of these folders. Tampering with them may cause some loss of data e.g., you might accidentally delete your bookmark from your browser but nothing has the potential to brick your system.