An IP address is a number or series of characters that helps network data reach the right device or online service. When you open a website, your device sends data toward the address of the server that hosts it, and the reply is sent back over the network.
Think of it like an address on a package: it helps the delivery find the right destination. A website name is easier for people to remember, so the Domain Name System looks up the matching IP address for your browser. Devices can also share or change addresses, so an IP address is not always a permanent label for one person.