What is a port in unix networking

[chinmaya]

plz let me know what is a port in unix networking
whether it a virtual thing or programming aspects.
we always use port with number,but what is port
mean what should be the definition of port
thanx with
regards
chinmaya

[vinot85]

Port in UNIX

Hi friend,
Port means a Logical way for Communication by any Protocol in the Networked Environment. Each Protocol has a specific port number to communicate with the system.
example,
HTTP - uses port number 80
FTP - uses port number 21
....etc
There are up to 65,535 ports available in a system.
In which they were classified in to 3 types,
1)Reserved Ports-(0 - 1023)
They are reserverd for specific protocols like HTTP -80, FTP -21..etc

2)Ephemeral Ports(1024-4999)
These are ports which a application program(typical ly a socket program can use). Used as a temporary communication medium.
3)Some ports are "Dynamic" in nature...

Regards,
Vinoth