When I say crash, it simply means that the whole system freezes and does not respond to any keyboard or mouse input. There are many reasons that can cause Ubuntu to crash. It could be due to hardware incompatibility (especially ATI/Nvidia graphics cards), a software conflict or when you run too many memory intensive applications at the same time.
In the event of a crash, the last thing that you want to do is to press the power off button. You could cause data loss, or even damage to the hard drive as the system could still be writing data to the hard drive
So what should you do if your Ubuntu crashes? Here are four things that you can do: