Way back in the day people used something called clay tablets to help them keep track of something important. Now days people use Tablets, Phones, Laptops, etc, To store things and help keep track of numbers, and etc. Phones need to be registered to work and sometimes need a card. These days people use Laptops, etc, to play video games. Back then to play when they made their first computer people had to wait half an hour or an hour to play now days Devices would be on in a flash! ;D. Phones, laptops/ PC / desktop computers, and tablets, were made after someone named Hollerith made a device called a unit tabulator, years later the company of Apple was built and they started to think what they could make with electricity? so they made computers that were slow.