Naming convention for the Solaris

Hello, I am new at this so please be patient and tolerant if I ask dump questions. Thank you

I want to understand the naming convention used by Sun for there solaris OS's. People use the name solaris 8 or Solaris 9 etc. How does this relate to the command line uname -X

For Example

bash-2.05$ uname -X

System = SunOS

Node = lcbrwebt

Release = 5.9

KernelID = Generic_118558-28

Machine = sun4u

BusType = <unknown>

Serial = <unknown>

Users = <unknown>

OEM# = 0

Origin# = 1

NumCPU = 2

[593 byte] By [confusd] at [2007-11-26 11:05:56]