Think it through together · A little story
A girl puts a long letter into several small envelopes and writes delivery information on each one. The robot explains that network data is often sent in small pieces too.
Lay out the process
- Header informationHelps with delivery
- Data sectionCarries part of the content
- Receive and processPass it to a higher-level program
A packet is a unit of data sent across a network. It can contain control information and the actual content.
In the envelope comparison, the delivery information on the outside is like a header, and the letter inside is like a payload. Different network layers have different formats and names. For now, remember the basic idea: information is divided into pieces and sent with clues about how to handle it.
A photo may span many packets, which the receiving side then processes according to the relevant protocols.
Your turn to try
If only a small part of a photo arrives, does the receiver definitely have the complete file?
Have you thought it through? Open for an explanation
No. It still needs the remaining data and the correct processing. Receiving some packets does not mean the full content is ready to use.
Take away one discovery
A packet is a unit of data sent across a network. It can contain control information and the actual content.
Try covering the diagram above and explaining each step to someone in your family. If one step is hard to explain, go back and look at that card again.