Sony lists Proxy among the PS5's advanced network settings, next to IP address, DHCP Host Name, DNS and MTU, and suggests asking your ISP or network administrator if those settings are unfamiliar. When it is on, the console sends its web requests, the ones that travel over HTTP and HTTPS, through the server you name instead of straight to the internet.
It leaves alone the traffic most players care about. Online matches and party chat use UDP and keep going direct, so a proxy will not lower your ping or change your NAT type. It does not change your PlayStation Store either: the store follows your account's country or region, which Sony does not let you change once the account exists.
Should you use one? On an ordinary home connection, no: leave it on Don't Use. Turn it on when the network you are on requires a proxy, as some schools, offices and hotels do, or when you run one yourself for a clear reason, such as filtering or logging the console's web traffic or keeping it on one fixed IP.



