Answer:
1. Clients and servers—how services such as e-mail and web pages connect using networks.
2. IP addresses—how devices on a network can be found.
3. Network hubs, switches and cables—the hardware building blocks of any network.
4. Routers and firewalls—how to organize and control the flow of traffic on a network.
The answer is The Internet. It is a vast global network that is made up of many smaller interconnected networks. It connects to millions of computer units world wide, in which any computer can communicate with any other computer as long as they are both connected to the Internet. It also made access to information and communication easier.
