An Internet Service Provider (usually called an ISP) is a company that sells you access to the internet. Just like a water company provides the water that flows through pipes to your house, an ISP provides the connection that lets data flow between your computer and the rest of the world's computers.

When you watch a video online, send an email, or play a multiplayer game, all that information travels through your ISP's network of cables and equipment. Your ISP connects your home to huge networks of fiber optic cables, cell towers, and data centers that make up the internet's infrastructure.

Some ISPs provide internet through cables buried underground, others through phone lines, and some through wireless signals from towers. The speed and reliability of your internet connection depends largely on your ISP and the type of technology they use.

Families typically pay their ISP a monthly fee, just like they pay for electricity or gas. The ISP decides how fast your connection will be (measured in megabits per second) and how much data you can use. Without an ISP, your computer or tablet could still work for offline tasks like writing documents or playing downloaded games, but you couldn't browse websites, stream shows, or connect to online friends.