Difference between Socket and Port

Although socket is not a port but it has close relationship with port. A socket is associated with a port, though a many-to-one relationship. Each port can have a single passive socket, awaiting incoming connections, and multiple active sockets, each corresponding to an open connection on the port.

Socket 
It is an endpoint of a bidirectional communication over a network.
It is associated with port. It is communication path to a port.


In a very simple term, we can represent a socket as :

Socket = IP Address + Port Number

It is just like a telephone connection (IP Address) with the extension(Port No).

Sockets are of two types :

Active Socket
It is connected to a remote active socket through a open data connection.

Passive Socket

It does not participate in an open connection, but wait for an incoming connection.

Port

It is a logical data connection that can be used to exchange data between client and server. 

It is represented through a port number starts from 0  and goes up to 65535.  

There are three different categories of Port Numbers:

0 - 1023 System Ports

1024 -  49151 User Ports

49152 - 65535 Dynamic Ports

System Ports are assigned by IETF (Internet Engineering Task Force) .

User Ports are assigned by IANA (Internet Assigned Numbers Authority ).

Dynamic Ports are not assigned.

If you are interested to know how we can create Client-Side and Server-Side Sockets in java, here is a link ..
Creating Client-Side and Server-Side Sockets in Java