Globally unique identifier (GUID - globally unique identifier), GUID is a 128-bit globally unique identifier (GUID - globally unique identifier), GUID is a 128-bit binary number (16 bytes), which can be used for All computers and networks that require unique identifiers. It is very unlikely that this identifier will be duplicated. The GUID has the format "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", where each x is a hexadecimal number in the range 0-9 or a-f.