A packet is a small amount of digital data sent over a network. When sending and receiving files across the internet. The Transmission Control Protocol/ Internet Protocol (TCP/IP) divides the files to an efficient size for routing and then chooses the best available route. This maintains the network efficiency at its best. For example, each e-mail you send goes as a series of packets and each one contains information that helps it arrive at a destination. This is called the control information. It contains the receiver’s IP address, the sender’s IP address, and the information that ties all the packets with data together. The data packets are called the payload (i.e. the content of the email).
Once all the packets are received, they are then reassembled into the original file by the TCP layer at the receiving end. It works just like a post office with the advantage of receiving and sending packets (instead of letters) at an extremely fast rate. Billions of packets are being sent and delivered each day taking only a relatively small amount of time to arrive.
The packets also contain error correcting information that will allow a certain amount of packets to be “lost” during transmission without the loss of data. If too many packets are lost then the data is unrecoverable. You may find this when you download a file and get a message there was an error, or try to open the file and find that it is corrupted.
You can also experience this when viewing a video stream online. Jittery images that breakup and skip some of the content can be due to packet errors or from packet loss. This happens when so many packets are lost or corrupted that the error correction process cannot retrieve all the information needed for a smooth playback. See the packet loss glossary entry for more information.« Back to Glossary Index