Backing up your iPad data is important just incase something happens to your tablet such as accidental damage or theft. The backup process also simplifies transferring data from your device to a new iPad in the event of an upgrade.
To write an updated iPad backup to your computer:
1. Connect the iPad to the computer with a USB cable.
2. Run iTunes.
3. Click on your iPad under DEVICES in the left menu.
4. Make sure the Summary tab at the top of the iTunes window is selected.
5. In the Backup section, check the "Back up to this computer" button.
6. Click the Sync button on the lower right.
You can also backup to iCloud to keep a copy of your iPad data on Apple's servers. You need to set up an iCloud account using your AppleID.