What is cloning?
One popular method of backing up is cloning. In cloning you make a copy of the entire hard drive or partition. This method is great for quick restore of your system but it is not very useful for the everyday task of backing up your files.
Acronis True Image is a very popular cloning tool and it is very easy to use but it is commercial software.
There are several many alternatives to True Image but the most popular is Clonzilla. Clonzilla is an almost perfect copy of the old Norton Ghost for DOS (no longer available). Clonezilla uses a Linux kernel for its back-end instead of DOS. It is not as user friendly as Acronis but it is free.