the devices that are person and that are yours, are an ipad and iphone, computer and others. If you had a personal device you would not want people going on your phone and looking on everything because you could have personal thing on things on there that you don't want people seeing because it's your own personal device.
the people who have stuff on there phone ,it might be illegal and they might not people want to see what is on there phone.
A mobile device is a small computing device. the devices that are peronal are the ones that you ues and that you only ues.