Protocols Basics

A protocol is a set of rules or procedures for transmitting data between electronic devices.
Protocols determine how data should be formatted, addressed, transmitted, received and acknowledged.
Without protocols, devices would lack the ability to understand the data they retrieve, rendering communication ineffective.
Protocols include TCP/IP, HTTP, SMTP, FTP, and POP3, among others.
Protocols can be implemented either by hardware, software, or a combination of both.

Types of Protocols and their Functions

TCP/IP (Transmission Control Protocol/Internet Protocol) is used to govern the connection of network devices on the internet. It is a two-layer program and handles both reliable delivery of data (TCP) and IP addressing (IP).
HTTP (Hypertext Transfer Protocol) is used for transferring files (text, graphic images, sound, video, and other multimedia files) on the world wide web.
SMTP (Simple Mail Transfer Protocol) is used for sending emails across the Internet. It can only send text and is used alongside protocols like MIME to send attachments.
FTP (File Transfer Protocol) is used for transferring files from one host to another over a network like the Internet.
POP3 (Post Office Protocol version 3) is used by email clients to retrieve email from a mail server.

Some protocols interact as part of an overall protocol stack or network suite. Examples of this include the internet protocol suite (TCP/IP) or the OSI model.
Protocols in these stacks serve specific purposes and interact with protocols above or below them on the stack.
For example, HTTP (a high-level protocol) utilises TCP/IP (a lower-level protocol) to deliver its data reliably across the internet.

Protocols often have built-in mechanisms to ensure the integrity, authenticity and confidentiality of data.
HTTP Secure (HTTPS) is a version of the HTTP protocol which uses encryption to protect the data being sent and received.
Protocols like Secure FTP (SFTP) and Secure Shell (SSH) also use encryption to keep data transmissions secure.