Data communication
Exchange of data between two devices via some form of transmission medium such as wire cable.
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Terminologies
- Message
- The information or data to be communicated.
- Sender
- The device that sends the data message.
- Receiver
- The device that receives the message.
- Transmission Medium
- The physical path through which a message travels from the sender to the receiver.
- Protocol
- A set of rules that governs data communication.
- It represents an agreement between communicating devices.
- Without a protocol, two connected devices may still be unable to communicate.
- For example, a person speaking French cannot be understood by a person who only speaks Japanese.
Network
- A network is two or more computers/devices that are connected together for the purpose of communication.
- A computer/device that is not connected to a network is called a stand-alone.
Advantages of Using Networks
| Advantage | Simple Explanation | Why it is convincing |
|---|---|---|
| File sharing | Users can share files easily with other users on the network. | Saves time because files do not need to transfer files using USB drives. |
| Hardware sharing | Users can share hardware such as printers. | Saves money because not every user needs their own printer or device. |
| Communication | Users can communicate through email, chat, or video calls. | Makes collaboration easier and faster, especially in schools or workplaces. |
Disadvantages of Using Networks
| Disadvantage | Simple Explanation | Why it is convincing |
|---|---|---|
| Cost | Extra equipment is needed to allow computers to communicate. | This can be expensive, especially for large networks. |
| Spread of malware | Viruses and other malware can spread easily across an improperly secured network. | One infected computer may affect many other computers on the network. |
| Hacking | Connected devices may be accessed without the owner’s permission. | This can lead to stolen, damaged, or leaked data. |
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Local Area Network (LAN)
- A LAN is a network that is geographically confined to one building or site.
- Examples include networks employed by small businesses, small organisations, schools, colleges, universities and homes.
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Wide Area Network (WAN)
- A WAN is a network that is spread over a wide geographical area.
- It can cover more than one site, across a country, or even across the world.
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Internetwork / internet
- When two or more networks, such as LANs or WANs, are connected, they form an internetwork or internet.
- Note: An internetwork is a private internet, written with a lowercase i.
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Internet
- The Internet is the global system of interconnected computer networks.
- It uses the Internet protocol suite, also known as TCP/IP, to communicate between networks and devices.
- It is a network of networks.
- It consists of private, public, academic, business, and government networks.
- These networks can range from local to global scope.
- They are linked by electronic, wireless, and optical networking technologies.
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Intranet
- An intranet is a private computer network used within an organisation.
- It helps to facilitate internal communication, collaboration, and access to company resources.
- It is restricted to authorised users within the organisation.