Windows variables
Variables that windows uses (that you can use too) as shortcuts for files / directories (folders), typed in-between percentage symbols (%).
These are examples of windows variables (windows 7) :
%ALLUSERSPROFILE% -- C:\\Program\\Data
%APPDATA% -- C:\\Users\\%username%\\AppData\\Roaming.
%USERNAME% -- Your user name that you are using.
%CMDCMDLINE% -- C:\\Windows\\system32\\cmd.exe
%COMPUTERNAME% -- Computer name
Of course there are a LOT more, but they are too many to list in here.
%ALLUSERSPROFILE% -- C:\\Program\\Data
%APPDATA% -- C:\\Users\\%username%\\AppData\\Roaming.
%USERNAME% -- Your user name that you are using.
%CMDCMDLINE% -- C:\\Windows\\system32\\cmd.exe
%COMPUTERNAME% -- Computer name
Of course there are a LOT more, but they are too many to list in here.