system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is an IP address? What do they do?

What are they? Do they change when you move? I am pretty sure they revolve around location but I've heard that they can change several times, that there's public and private IP's, and a load of other things.
gpt
An IP address is like a phone number. Picture you're at your old school house phone, and you want to get some information from another caller (website). You can either dial the persons number directly, if you memorized it, but you probably don't. phone numbers can change, so can IP addresses. Most likely you'll look up the 'phone number' with a directory book - this is DNS. DNS maps names (i.e. google.com) to an IP address (172.217.2.78). Your computer/phone understands how to connect to that phone number/IP address, and communication (two directions) is established. Without an IP address/phone number, you can't communicate.