what is a guid
A globally unique identifier (GUID, /ËÉ¡wÉªd/ or /ËÉ¡uËÉªd/) is a unique reference number used as an identifier in computer software. GUID can be stored as a 16- byte (128-bit) number; Microsoft defines a format which is split into four fields, defined as follows. Note that this format differs from the UUID standard only in the byte order of the first 3 fields.