A globally unique identifier (GUID) is a 128-bit value consisting of one group of 8 hexadecimal digits, followed by three groups of 4 hexadecimal digits each, followed by one group of 12 hexadecimal digits.


GUIDs are the Microsoft implementation of the distributed computing environment (DCE) universally unique identifier (UUID).


The following is an example of a GUID


6B29FC40-CA47-1067-B31D-00DD010662DA