What is Protocol in Networking?

Protocol is a set of rules for efficient data communication over a network. In a network, communication occurred between different systems that are capable for sending or receiving data. But all systems are not able to send to receive data as we expect. For this, all system should be agree on a protocol. 

Protocols defines:

How to find destination IP addresses?

How to send data back and forth?

When to communicate and so on.

Protocols exist at various different level of journey of overall communication. In the OSI model and TCP/IP model, protocols presents in each layer for different functions. There should be the same protocol on both sender and receiver side.

A protocol has some key elements:

Syntax : The 'syntax' defines the structure and format of data. It defines how data is represented.

Semantics : It defines how data is interpreted what action to take based on interpretation. 

Timing : Timing defines how fast data would be sent and when to send data.

Some Protocols are:

FTP File Transfer Protocol

SMTP Simple Mail Transfer Protocol

TCP Transmission Control Protocol

Telnet Teletype Network

HTTP Hyper Text Transfer Protocol

HTTPs Secure Hyper Text Transfer Protocol

POP Post Office Protocol

HTCPCP Hyper Text Coffee Pot Control Protocol

MTP Media Transfer Protocol

SFTP Secure File Transfer Protocol

SSL Secure Socket Layer

TLS Transport Layer Security

E6 Ethernet globalization protocols

NTP Network time protocol

PPP Point to Point Protocol

NNTP Network News Transfer Protocol

QOTD Quote Of The Day

IMAP Internet Message Access Protocol