Closed-loop systems are able to correct in order to meet target results. Normally a sensor is used to look at the output and adjust the process accordingly. This is called feedback.
A file with an extension of .DAT is known as a Data (General). These .DAT files can be opened on Windows and Apple using programs ...
NTUSER.DAT files are absolutely essential. NTUSER.DAT files are the HKEY_CURRENT_USER hive for the registry. One NTUSER.DAT for each user on the machine, some templates and repair.