Any device that connects to the Internet---desktop computer or laptop, mobile phone or tablet---uses the Internet Protocol (IP) to communicate online. To connect to the Internet, each device needs a unique address (sort of like a street address). This IP address is generally visible to the apps and services you use online, but can also be useful to advertisers, Big Tech, and others to identify you online. If you want online privacy, hiding your IP address is a good place to start.