Page 11 - Handout Computer Network.

Figure 1-2shown a wide-area networks Hierarchy

Every Networking Concept Explained In 8 Minutes

https://www.youtube.com/watch?v=tSodBEAJz9Y&t=8s

1.2 The Fundamentals of Internet Connectivity

To understand the role that computers play in a networking system, consider the Internet.
The Internet can be thought of as a tree with computers as leaves. Computers are the sources
and receivers of information by way of the Internet. Computers can function without the Internet,
but the Internet cannot exist without computers. The Internet is growing rapidly, and users are
becoming increasingly dependent on it for a myriad of services. Computers, along with being an
integral part of a network, also play a vital role in the world of work. Businesses use their
computers for a variety of purposes, but they also use them in some common ways. They use
servers to store important data to manage customer and employee accounts. They use
spreadsheet software to organize financial information, word processor software to maintain
records and correspondence, and browsers to access internal and external websites. High-speed
accesses to the Internet, such as cable modem and DSL services, are now available to the home
and small office, which is increasing the demand for support services. No longer satisfied with a
single computer connected to the Internet, the consumer needs the tools to be able to share the
connection. The Internet is the largest data network in the world. The Internet consists of a
multitude of interconnected networks, both large and small. At the edge of this giant network is
the individual consumer computer.
Connection to the Internet can be broken down into the following components:

• The physical connection—A physical connection to a network is made by connecting
a specialized expansion card, such as a modem or a network interface card (NIC), to a
PC with a cable. The physical connection is used to transfer signals between PCs in the
local network and remote devices on the Internet.

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