Your public IP address is the unique code that identifies your network to the wider internet. Think of how your home address allows other people to send you mail, deliver food, or come to your home to visit. An IP address is similar in that it tells other networks where to send data that you request.
It’s normal for a public IP address to change occasionally, such as when you reset your router. That’s because your internet service provider (ISP) assigns your IP address dynamically, so you may get a different address when you turn your router back on. A dynamic IP address is fine for most people, but some may need a static public IP to host or access certain services.
There are also private IP addresses, which are assigned by your router’s DHCP server to identify different devices on your network. Computers, phones, printers, and other web-enabled devices all receive private IPs. You might set up a private static IP for convenience if you want certain devices to keep the same private IP addresses within your network.