1. Computer Technology Notes #4
Networks
Computer Technology Notes #4

2. Network
A network is two or more computers and other devices (printers or scanners) that are connected, for the purpose of sharing data and programs

3. Advantages of Networks
Communication
, chat rooms, telephone, video telephone, video conferencing
Sharing hardware
Printers
Sharing files and data
Users can access data from other computers on the network, including the server

4. Advantages of Networks
Sharing software
Users can run programs from remote computers on the network
Security of data
Information preservation

5. Network Terms File Server Host Computer
A computer connected to a network that distributes resources to other users
Contains the software to manage and process files for other network users
Host Computer
Refers to any computer that provides services to network users
This term is used more commonly with computers on the Internet
IBM Server Commercial

6. Network Terms Workstation Client
Refers to a personal computer connected to
a network
Example
Each computer in the classroom
Client
Refers to the software on a computer that allows the user to access the server
Example: Windows

7. Network Interface Card (NIC)
Small circuit board that converts the digital signals from a computer into signals that can travel over a network
Desktop Computers have the NIC inside the case with a port on the outside for the network cable
Example:
Our classroom computers

8. Network Connection Devices
Hubs (Switches)
A device that connects several components of a network
Routers (Gateways)
A device that connects at least two networks

9. Firewalls This is part of a network that is designed to block
unauthorized access
to the network while allowing authorized access
Firewalls can be implemented in software or hardware or both

10. Physical Infrastructure
Physical infrastructure refers to cables, modems, switches, and routers.
Twisted-pair – Two insulated wires twisted around each other; the same type of wire as that used for telephones

11. Physical Infrastructure
Coaxial cable – Consists of an insulated center wire surrounded by a layer of braided wire; the same type of wire as that used for cable TV
Fiber-optic cable – Type of fiber glass cable that transmits data in the form of light impulses; can carry more data for longer distances than other wire

12. Wireless Networks (no wires involved)
Wireless communication across networks or within a network can be achieved through the following technologies:
Satellite
Microwaves
Radio waves (cell phone systems, wireless LANs, home networks)
Infrared technology-must
be in a line of sight, such as a mouse

13. Bandwidth
Bandwidth is the amount of data that can be transmitted through a communications channel.
Digital bandwidth is measured in bits per second (bps), kilobits per second (Kbps), megabits per second (Mbps), or gigabits per second (Gbps).

14. Local Area Network (LAN)
Computer network that is located within a limited geographical area, such as a school or small business
Example:
The network in our classroom

15. Wide Area Network (WAN)
Interconnected group of computers and peripherals that cover a large geographical area, such as multiple buildings
Examples
The Jordan School District Network
The Internet

16. Packet Switching Demonstration
The Internet is a packet switching network:
Outgoing messages are divided into fixed-size data units called packets.
Packets are numbered and addressed to the receiving computer.
Routers examine the packets and send them to their destination.
Packet Switching Demonstration

17. IP Addresses
A unique identifying number assigned to each computer connected to the internet
Example –
Each computer on a network should have its own separate IP Address or conflicts will occur when there are duplicate addresses