That’s done by DNS. The DNS server examines your DNS query and sends you back an IP address answer that’s “close” to the requesting IP address.
For example, if you are in country X, then even though there are dozens or hundreds of POP addresses for the name you requested, you’ll be answered with one for country X.
For example, if you are in country X, then even though there are dozens or hundreds of POP addresses for the name you requested, you’ll be answered with one for country X.