UUIDs are a 128 bit, unique number. When written for humans to read, they are presented as a stream of base 16 numbers: b571b82f-59e8-4400-8ea6-8e0c30216716.
The URL for this page you will also see an application of a UUID:
UUIDs are great because unlike other number systems, you can get by without a central authority doling them out. A piece of industrial equipment can just make one up. A database can invent one if it needs to refer to a new entity. A website can just generate one, and not have to worry about the title on the page changing, or how he page would even fit into a filing system. You also don't have to explain the gap between unit 1000000003 and 1000000005 if 1000000004 failed it's quality control inspection and was sent off for recycling.
UUIDs used within the construction of the Iliad use a hashed namespace combined with a serial number. The Vessel itself is assigned the UUID of: bb960b36-f027-4208-85d0-8d7b83179a6d
Production scripts in the software engine use