Networking - Packet – A Small Unit of Data Transmitted Over a Network

A packet is a small piece or unit of data that is sent over a network, such as the internet. When you send or receive information online — like loading a webpage, sending an email, or watching a video — the data is not sent all at once. Instead, it is broken into many smaller parts called packets.

Each packet contains:

1. Data (the actual content) – a small piece of the information being sent, such as part of a web page or a video file.

2. Header information – details about the packet, like where it came from, where it is going (source and destination addresses), and the order it belongs in.

You can think of packets like letters sent through the mail:

• The letter is the data you want to send.

• The envelope has the address and other information needed for delivery.

• When all letters (packets) reach their destination, they are put together to form the complete message or file.

For example, if you are downloading a photo, the image is divided into many packets. These packets travel separately across the network and might even take different paths. Once they all arrive at your device, your computer reassembles them to create the complete picture.

In short:

• A packet is a small, manageable piece of data used to make network communication faster and more efficient.

• Sending data in packets helps prevent congestion, makes error detection easier, and allows information to reach its destination even if some network paths are busy.