A packet is also known as the datagram. It consists of control information and the data of the user. With this control information, it helps provide data to deliver the payload. Typically, this control information can is found in the packet headers and trailers. The unit of data is routed between an origin and the destination on the internet or even to any other packet-switched network.[1] This is a container or a box that carries the data over a TCP or IP network and internetworks.

A packet is also considered as the most fundamental logical arbitration of the data that is passed over a secure network. Moreover, it represents the smallest amount of data that can traverse over a system at a single time. A TCP or IP network packet contains several pieces of information which include the data that it is carrying, the source destination of IP addresses, and any other constraints that are required for quality of service and packet handling.[2]


When a node on a particular network sends data over the web, it will transfer the packet data frame across a switch before reaching a router. After looking at the destination IP addresses, the router will encapsulate the data and will route it towards the recipient. The data that will be encapsulated in the packet that will be forwarded over the network. The packets have two distinct types of information to reach the destination entirely and correctly. These are control information and the information that it will be carrying. The control information has the source destination addresses, sequencing format, error detection, and correction mechanisms, all of this help to ensure the optimal delivery if the data. It is usually located in the header and trailer that will encapsulate the user data in between them.

Furthermore, a packet typically contains a source, destination, data, size, and any other useful information that will help the packet make it to the appropriate location and get appropriately reassembled. The data that will be transferred over the internet will be sent as one or more packets. The most common packet sent is the TCP packet. The size of the packet is just limited, so most of the data that will be sent over a network will be broken up into multiple packets before being sent out, and they will be put back together when received. When a packet is already transmitted over a network, the network routers and network switches will then examine the packet and its source to help it direct to the correct location.[3] During the transmission, the network packets can be dropped. If a packet will not be received or if there will be an error that will occur, it will be sent again.

Packet Structure

The exact structure of a packet depends between the protocols; a regular packet typically includes two sections, a header, and a payload. Payload section of a packet has the actual data that is being transferred;[4] this is sometimes a minor portion of a file, page of a website or other transmissions since the individual packets are only relatively small also. The primary function of these packets is to conduct the transfer of data effectively across a network. Breaking up a large file into smaller packets will contribute to ensuring that each section will be transmitted successfully. If a packet will not be received or will be dropped, only those dropped packets are needed to be resent. If transferring a data will encounter network congestion because of several simultaneous transfers, the remaining packets can be rerouted by the help of a less congested path.

Packets vary according to the structure and its functionality depending on the protocols that will be implementing them. The part of switching the packets flushes the packets on the internet, and each of them finds its way to the destination is more efficient to send the packet.[5] This mechanism utilizes the underlying structure of the internet for free, which is considered as the main reason for which the VoIP calls and the internet calling are most free or very cheap. The bottom line is that the data travels in packets over digital networks and all of the data that we consume whether it will be text, audio, images, or video, come broken down into packets which are reassembled in our devices or computers. This is the reason why for some instances if a picture loads over a prolonged connection, chunks can be seen appearing one after the other.

If any file is sent from one place to another place on the internet, the TCP will divide the data into chunks of an efficient size for routing. This packet-switching scheme is one of the most efficient ways to handle transmissions on a connectionless network such as the internet.


  • Header – it contains instructions about the data that will be carried by the packet.
  • Payload – also knowns as the body or data of the packet. This is considered as the actual data that the packet will be delivering to the destination.
  • Trailer – sometimes called the footer, it usually contains a couple of bits that will tell the receiving device that it has reached already the end of the packet.


Donald Davies first coined the term packet in the year 1965. It is used to describe a segment of data that is sent from one computer or device to another over a network.[6] It is used because it divides the data into chunks, which helps the information more efficiently and keep the network resources from being tied up by a single, larger file.

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