Computers are everywhere: at school, in our homes, and in factories and offices. Many people have a mini-computer in their pocket! This engaging series looks at computers and their uses, with an emphasis on the STEM principles that underpin how they work.   A smartphone is a portable computer that fits in your pocket. It lets you make phone calls and send text messages, like a regular cell phone. But a smartphone can also connect to the internet, play games, and run apps. Find out how smartphones developed, how they work, and how people use them.