UUIDs (Universally Unique IDentifiers), also known as GUIDs (Globally Unique IDentifiers), can be used to uniquely identify rows in a table. The values are generated such that a value produced on one computer will not match a value produced on another computer. UUIDs can therefore be used as keys in replication and synchronization environments.
For more information, see “NEWID function [Miscellaneous]” in Chapter 4, “SQL Functions,” or the UNIQUEIDENTIFIER data type in the section Binary data types in Chapter 3, “SQL Data Types,” in Reference: Building Blocks, Tables, and Procedures.
