Internet Technology

Definition of Network : A network is a collection of computers and devices connected together via communications devices & transmission media allowing computers to share resources.

Definition of Communication Device : Hardware components that enables a computer to send and receive data, instruction, information to and from one or more computers.

Definition of Transmission Media : The type of physical system used to carry a communication signal from one system to another.

Advantages of Network : 

• Hardware sharing - network facilitate the sharing of hardware device such as printer, plotters and modem
• Data sharing - enable many people to access and share the same data such as database & group software development
• Connectivity & Communication : Network connect computers and the users of those computers
• Internet access sharing - small computer networks allow multiple users to share a single Internet connection.

Disadvantages of Network :

• Undesirable sharing - viruses are easily spread over network and the internet
• Data security Concerns - unauthorized access and sabotage
• Security issues - a computer hacker can get unauthorized access by using different tools
• Expense/cost - expert support needed.

Types of Network Architecture 

i) Peer-to-peer

Definition : a network model in which all computer can function as clients or server as needed, and there's no centralized control over network resources.

Example : A computer can act as a server by sharing a printer it's connected to and at the same time act as client by accessing a file shared by another computer on the network.

Advantages of a Peer-to-peer network :

• Less startup cost to setup the network architecture
• Easy to install and configure for the computers in the network
• When a peer fails it will not affect other peers so the network is reliable 

 Disadvantages of a peer-to-peer network :

• Decentralized
• Less security
• Every user is taking care is his/her own machine

 ii)  Client-Server Network

Definition : Network in which one powerful computer coordinates and supplies services to all nodes on a network.

Advantages of Client-server network :

• Centralized
• Scalability
• Better management files
• Accessibility

Disadvantages Of Client-Server network :

• Expense
• Maintenance
• Dependence 

Types of Network Topology 

A network topology refers to : The layout of the computers and devices in a communication network.

3 basic types of network topology :

i) Star Network - All the computers and other devices on the network connect to a central devices, thus forming a star.

ii) Bus Network - Consists of a single central cable, to which all computers and other devices connect.

iii) Ring Network - on a ring network, a cable forms a closed loop with all computer and devices arranged along the ring.