Ports are logical channels that the TCP/IP suite uses for communication purposes
Specific processes/applications have dedicated ports from numbers 0-65535, however, the common ones are:
|21 - Control |
20 - Data Transfer
|22||Encrypted data exchange|
|23||Remote logging in for terminal servers|
|53||Resolves host names to IP addresses|
|67||Automatic IP addresses assignment|
|443||Insecure internet traffic|
|3389||Remote access of clients|
When an IP Address is combined with a network port it is called a socket.
Ports can be blocked by firewalls which will ultimately prevent devices using the ports designated process.