For the Linux Operating system, there are 3 different kinds of network service ports:
- The Well Known Ports (0-1023) – which are reserved for the operating system and core services.
- The Registered Ports (1024-49151) – which can be used by applications, specific services, and users.
- The Dynamic and/or Private Ports (49152-65535)
There is a standard list of these network service port assignments for Linux documented at:
The Well Known Ports are listed in the /etc/services file on the OS. Specific ports used by applications etc can be added to the /etc/services file.