HowTo: Find Out My Linux Distribution Name and Version

How do I find out what version of Linux distribution I'm using from the shell prompt?

To find out what version of Linux (distro) you are running, enter the following command at the shell prompt:
$ cat /etc/*-release
Sample outputs on Ubuntu v11.04:

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=11.04
DISTRIB_CODENAME=natty
DISTRIB_DESCRIPTION="Ubuntu 11.04"

lsb_release Command

The lsb_release command displays certain LSB (Linux Standard Base) and distribution-specific information. Type the following command:
$ lsb_release -a
Sample outputs:

No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 11.04
Release: 11.04
Codename: natty

How Do I Find Out My Kernel Version?

Type the following command:
$ uname -mrs
Sample outputs:

Linux 2.6.38-8-generic i686

Where,

1. Linux - Kernel name
2. 2.6.38-8-generic - Kernel version number
3. i686 - Machine hardware name (32 bit)