Red Hat

Guys,
How to find OS version and firmware version in LINUX?

Like in AIX.

uname -a will show me the version 5.3, 6.1,7.1.
lsmcode -c will show me - system firmware image as SF240_417.


What are the similar commands in Linux.
I checked uname -a and cat /etc/release.

uname -a
Linux xxxxxx 2.6.32-279.22.1.el6.x86_64

# cat /etc/redhat-release
Red Hat Enterprise Linux Server release 6.3


What do they mean?

If I want to upgrade my OS which versions among these would change?

Also whats Firmware level? is firmware level referred to as Kernel level?

I am basically an AIX person. Hence I have these questions.

I was up to say as you did..

Code:

#uname -a

and

Code:

#cat /etc/redhat-release

I don't thing there is something else, as I know!