If you are asked a question like - How will you find whether the Linux distribution installed in a PC is Ubuntu or Fedora, what would be your answer?
Before answering something like Ubuntu is orange while fedora will look blue, remember that Linux is the most customizable operating system out there. You can modify the look and feel of the system to any extend, limited only by your imagination. You can make a Fedora installation look like Ubuntu and vice-versa.
How would you know what Linux distribution you are running?
Take a terminal and enter the below command:
(Note - You can use this command to know whether you have successfully updated to Ubuntu 8.04 or not after a system upgrade)
This will give you all information like the Distribution name, version, code name etc.
Note that this utility simply reads out the contents of the file /etc/lsb-release. So simply printing this file will also give the same information.
In case the above utility is not installed, try
which will give you the details of the installed kernel and the distribution name.