uuidgen function unique identification code

[root@localhost ~]# uuidgen 
6393ddf2-84ee-4f9b-b38e-0355356778ba

[root@ localhost ~]# cat /proc/sys/kernel/random/uuid 
fb9370df-d629-4ece-a45e-611a6d6a5d9c

　Features:

      Code name is UUID Universally Unique Identifier (Universally Unique Identifier, UUID),

　format:

    32 contains 16 digits to "-" connected number is divided into five sections, in the form of 32 characters 8-4-4-4-12. Examples; 550e8400-e29b-41d4-a716-446655440000