UUID is the abbreviation of Universally Unique Identifier. It is a standard for software construction and a part of the Open Software Foundation in the field of distributed computing environments. UUID is a 128-bit value, which can be calculated through a certain algorithm. To improve efficiency, commonly used UUIDs can be shortened to 16 bits. UUID is used to identify attribute types and is regarded as a unique identifier across all space and time. Generally speaking, it is guaranteed that this value is truly unique and any UUID generated anywhere will not have the same value. One benefit of using UUIDs is that new identifiers can be created for new services. The standard UUID format is: xxxxxxxx-xxxx-xxxx-xxxxxx-xxxxxxxxxx (8-4-4-4-12).