Basic

Computer Knowledge

Outline Notes 1 Notes 2 Assessment

Notes 21. Introduction to

Networks

2. Network Topology

3. Types of Network

Notes 24. Advantages and

Disadvantages of Networks

5. Broadband vs. Dialup Connections

Introduction to Networks

A network…is a collection of computers and devices linked together via cables.

Parts of a Network A network comprises of computers, peripherals, network cards for the purpose of communications.

Parts of a Network (1) The computers connected to a network are the workstations.

Parts of a Network (2) File server stands at the heart of networks.

Parts of a Network (2) The file server controls the communication of information among computers on a network.

Parts of a Network (3) Cables are the wires that link up the computers and equipment on a network.

Parts of a Network (3) There are two kinds of cables:co-axial cablefibre-optic cable

Parts of a Network (4) The network interface card is a device that connects each computer to a network.

Parts of a Network (4) This card controls the flow of information between the network and the computer.

Parts of a Network (5) A hub is a device that provides a central location where all the cables on a network come together.

Activity: Parts of a Network Fill in the boxes with the names of the different parts of a network.

Activity: Parts of a Network File

serverworkstation

workstation

scanner

printer

workstation

Network TopologyNetwork topology is the specific physical arrangement of the devices of a network.

Network TopologyThe devices of a network can be arranged in many ways.

1. Ring Topology

2. Star Topology

Network TopologyRing Topology

Network TopologyStar Topology

Types of Network Two types of network:

1. Local Area Network (LAN)

2. Wide Area Network (WAN)

Local Area Network (LAN)

A network that connects computers in a small geographic area.

Wide Area Network (WAN)

A network that connects computers in a large geographic area.

Wide Area Network (WAN)

WANs are generally formed by connecting LANs together.

Wide Area Network (WAN)

Internet is a kind of WAN that connects thousands of networks around the world.

Advantages and Disadvantages of Networks

Advantages of Networks

Sharing of peripheral devices/Sharing of hardware

Expensive devices such as laser printers or scanners can be shared.

Advantages of Networks

Sharing of data…

Data files such as documents and images can be shared and transferred among users easily.

Advantages of Networks

Sharing of software…

Some of the popular software programs are available at a lower price.

Advantages of Networks

Flexible access…

Users can get back their files from any workstation.

Disadvantages of Networks

Expensive to install…

Buying the network cables, network cards, and software are expensive.

Disadvantages of Networks

Require administrative time

Managing a network requires some training. Usually a network administrator needs to be employed.

Disadvantages of Networks

File server may fail…

Since the file server is at the heart of the network, the network will not function when the file server breaks down.

Disadvantages of Networks

Cables may break…

There are cases where one broken cable can stop the entire network.

Broadband vs. Dialup Connections

Two kinds of internet connections:

1. Dialup Connection

2. Broadband Connection

Dialup ConnectionsThe term dialup relates to accessing the internet via telephone lines.

Dialup ConnectionsWhen computers exchange information through telephone lines, a modem has to be used.

Dialup ConnectionsMODEM stands for…

MOdulator-DEModulator

Dialup ConnectionsDialup was the most common way to access the Internet in the 1990s, because of its low cost.

From Dialup to Broadband

Dial-up is gradually fading out because of several factors:

1. Limitation of phone lines

From Dialup to Broadband

Dial-up is gradually fading out because of several factors:

2. File size of the web content is getting larger

From Dialup to Broadband

3. Desire for a faster connection speed

Broadband Connections

High-speed Internet connections are sometimes referred to as broadband connections.

Advantages of Broadband Connections

1. Frees up Telephone Line

A high-speed connection does not hold the telephone line when users go online.

Advantages of Broadband Connections

1. Frees up Telephone Line

Therefore, it allows users to talk on the phone or use a fax machine while going online.

Advantages of Broadband Connections

2. 24-Hour Connection

Users can connect to the Internet 24-hours a day.

Advantages of Broadband Connections

3. Fast Access

Quick access to data, sound and image files on the Internet

Trend of Broadband Connections