Lesson 24
Network Fundamentals
Computer Literacy
BASICS: A
Comprehensive Guide
to IC
3, 3
rdEdition
Lesson
24
Objectives
Describe a network.
Explain the benefits of a network.
Identify the risks of network computing.
Describe the roles of clients and servers on a network.
List and describe the types of networks.
List and describe communications media and hardware.
Lesson 24
Vocabulary
biometric security measures cable modem client client/server network communication channels digital subscriber line (DSL) extranet firewall hacker hub Internet intranet
local area network (LAN)
Lesson 24
Vocabulary (continued)
node peer-to-peer network proxy server Public Switched Telephone Network (PSTN) router server server operating system
T-1 line
wide area network (WAN)
WiMAX
wireless Internet service provider
(WISP)
Lesson
24
Introduction
Connecting computers through a network, a
group of two or more computers linked together,
allows users to share software applications and
to share hardware devices such as printers,
scanners, and other hardware add-ons.
Companies and organizations use networks to
connect employees and subsidiaries nationally
and even internationally.
Lesson
24
Introducing Networks
The Public Switched Telephone Network (PSTN) supports telephone service and is the world’s collection of interconnected commercial and government-owned voice-oriented systems.
Lesson
24
Network Benefits
The biggest network of all is the Internet.
Network benefits include:
– Information sharing
– Collaborative environment
– Hardware sharing
– Software sharing
Lesson
24
Risks of Networked Computing
As with any technology, disadvantages also
exist. Disadvantages of networks include:
– Individual loss of autonomy
– Malicious code
– Network faults
– Setup and management costs
Lesson
24
Client/Server Networks
The term client/server network describes a software architectural model relationship.
In most instances, the client is a software program such as Internet Explorer. The server is hardware and can be one of many types of servers, such as a mail server, a database server, an FTP server, an application server, or a Web server.
Server operating systems are high-end programs
designed to provide network control and include special functions for connecting computers and other devices into a network.
Lesson
24
Network Types
Networks are divided into two main types:
local area networks (LANs) and wide area
networks (WANs).
Lesson
24
Local Area Networks:
Most LANs connect
personal computers,
workstations, and other
devices such as
printers and scanners
in a limited
geographical area.
Network Types (continued)
Lesson
24
Network Types (continued)
Wide Area Networks:
A WAN covers a large geographical area and can contain
communication links across metropolitan, regional, or national boundaries.
Network types include:
– Client/server network: Server manages resources
– Peer-to-peer network: All computers are equal
– Intranet: Used within an organization
Lesson
24
Network Communications
Communication Hardware:
Communication hardware devices facilitate the transmitting and receiving of data. Examples are:
– Modem: Converts analog signals to digital and vice versa
– Cable modem: Uses coaxial cable
– Digital subscriber line: Uses ordinary phone lines
– T-1: Type of fiber-optic telephone line
Lesson
24
Network Security Issues
Passwords are the most common form of restricting access to data.
Establishing and maintaining computer security is necessary to keep hardware, software, and data safe from harm or destruction.
Lesson
24
Network Security Issues
(continued)
Other security measures include:
– Electronic identification cards
– Firewalls to protect companies’ networks from
external networks
– Antivirus software
– A proxy server that acts as an intermediary between a user and the Internet.
Lesson
24
Network Security Issues
(continued)
Planning for Security:
Companies must plan for security before it is
needed
– Institute a selective hiring process.
– Regularly back up data and store it off site.
Lesson
24
Network Security Issues
(continued)
Wireless Security:
Wireless networking
is very common, but
has many security
issues and hackers
have found it very
easy to access
Lesson
24
Summary
In this lesson, you learned:
A network is a group of two or more computers
linked together.
A telephone network is similar in makeup to a
computer network. The Public Switched
Telephone Network (PSTN) supports telephone
service, and it is the world’s largest collection of
interconnected commercial and
government-Lesson
24
Summary (continued)
You can use a network for information sharing, hardware sharing, software sharing, and as a collaborative environment.
Networks are divided into two main types: local area networks and wide area networks.
Local area networks (LANs) connect personal
computers, workstations, and other devices such as printers and scanners in a limited geographical area, such as an office building, a school, or a home.
Lesson
24
Summary (continued)
A wide area network (WAN) is made up of several
connected local area networks.
In a client/server network, one or more computers
on the network act as a server. The server
manages network resources. In a peer-to-peer
network, all of the computers are equal. No
computer is designated as the server. People on
the network each determine what files on their
Lesson
24
Summary (continued)
Data security is a risk with many networks. Some risks to computers are natural causes, some are accidents, and others are intentional.
The best way to protect data is to effectively control the access to it. Generally, this protection is the
responsibility of the network administrators and security personnel. If unauthorized persons gain
access to data, they may obtain valuable information or trade secrets. Hackers are people who break into computer systems to steal services and information.
Lesson
24
Summary (continued)
Transmission media can be either physical or
wireless.
