Most applications communicate over a TCP or UDP port. Ports 0-1023 are usually privileged and require administrator or superuser access to bind a network socket to an IP with the corresponding port. But anything over 1024 is up for grabs. IANA (Internet Assigned Numbers Authority) can “reserve” ports for specific applications — but this is only a formality; users and applications are free to use whatever port they wish.
So a look at some port numbers (1024+) and how they are used as default por