How to find Ubuntu and kernel version?

Ubuntu version:

# cat /etc/issue
Ubuntu 10.04 LTS \n \l

or

# cat /etc/lsb-release
DISTRIB_ID=UbuntuDISTRIB_RELEASE=10.04DISTRIB_CODENAME=lucidDISTRIB_DESCRIPTION="Ubuntu 10.04 LTS"

Kernel version:

# cat /proc/version
Linux version 2.6.18-194.26.1.el5.028stab070.14 (root@rhel5-build-x64) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-46)) #1 SMP Thu Nov 18 16:34:01 MSK 2010

or

# uname -a
Linux 207843 2.6.18-194.26.1.el5.028stab070.14 #1 SMP Thu Nov 18 16:34:01 MSK 2010 i686 GNU/Linux