Its better to protect your iPad with a passcode and iOS provides passcode lock option to protect your iPad, either you can set up a numeric or alphanumeric passcode on your iPad. When you set password on iPad 2, nobody can use your iPad or access data without entering password, follow the given steps to protect you iPad with a passcode. You can use this guide either on iPad 2 or iPad 1.
On your iPad tap “Settings” icon
Tap General > Passcode Lock
Tap “Turn Passcode On” and enter four digit passcode and then re-type to confirm it.
If you want to set a bit difficult passcode on iPad then turn Off “Simple Passcode” option and use alphanumeric passcode.
Now when you try to use your iPad, you need to enter password first.