Rooting and flashing of Custom ROMs is a very common procedure that is used by the Android users. While rooting will not result in any loss of data, flashing a custom ROM will erase all the data on the Android device because a factory reset has to be performed. So it is essential that a backup of all the apps and the data is made prior to installing a custom ROM. Now there are two ways of creating a backup. One is using the Titanium Backup to make a backup of all apps and data and other is a Nandroid Backup.