Linux: How to retrieve and change partition`s UUID

A Universally Unique Identifier (UUID) is an identifier standard used in software construction, standardized by the Open Software Foundation (OSF) as part of the Distributed Computing Environment (DCE).

How to retrieve UUID

On some unix systems a hard drives partition is referred by to as UUID instead of the location of the it relevant block device file for example like in /etc/fstab:

UUID=03136e34-6187-4720-8594-b27508ef978f /boot ext3 defaults,noatime 1 2

In this case it would be harder to find which partition is mounted behind /boot. Here are some ways how to retrieve relevant partition UUID.