Sockets allow communication between two different processes on the same or different machines.
It's a way to talk to other computers using standard Unix file descriptors.
To a programmer, a socket looks and behaves much like a low-level file descriptor.
This is because commands such as read() and write() work with sockets in the same way
they do with files and pipes.
A Unix Socket is used in a client-server application
framework. A server is a process that performs some functions on request from a client. Most of the
application-level protocols like FTP, SMTP, and POP3 make use of sockets to establish connection
between client and server and then for exchanging data.
The two main types of sockets are:
a. Stream Sockets: Delivery in a networked environment is guaranteed. If you send through
the stream socket three items "A, B, C", they will arrive in the same order: "A, B, C".
These sockets use TCP (Transmission Control Protocol) for data transmission. If delivery
is impossible, the sender receives an error indicator. Data records do not have any boundaries.
b. Datagram Sockets: Delivery in a networked environment is not guaranteed. They're connectionless
because you don't need to have an open connection as in Stream Sockets - you build a packet with the destination
information and send it out. They use UDP (User Datagram Protocol).
We have added two animations to demonstrate the working of eavh of the sockets. Please hover over
"Select the Communication type" dropdown to select:
TCP for Stream Sockets.
UDP for Datagram Sockets.