Vidaan Academy

Computer Fundamentals – Information Processing Fundamentals

What is a Network?

A network is a group of devices connected wirelessly or through cable that can share hardware and resources such as printers and software between many computer users.

All networks consist of:

  • Server or File Server – A computer system with the primary purpose to host files and/or applications and provide access to them on a network.
  • Workstations – Computers connected to the file server that depend on it.
  • Cables – Used to connect network interface cards in each computer.
  • Wireless – Popular technology in networking; more effective than wired technology in many instances.

Advantages of Networking Computers

  • Speed – Sharing and transferring files within networks is rapid, saving time and maintaining file integrity.
  • Cost – Networkable versions of software are cheaper and easier to maintain.
  • Security – Sensitive files and programs are password protected.
  • Resource – Resources such as printers and fax machines can be shared.
  • Email – Enables staff to communicate without leaving their desks.

Disadvantages of Networking Computers

  • Server faults stop applications from being available.
  • Network faults can cause loss of data and resources.
  • User work is dependent upon the network.
  • System can be open to hackers.
  • Decisions tend to become centralized.
  • Network can become inefficient or degrade in performance.

Types of Network

  • Local Area Network (LAN)
  • Wide Area Network (WAN)
  • Metropolitan Area Network (MAN)

Local Area Network (LAN)

LANs cover a small area, used in schools, small offices, or homes. They are typically created with Ethernet or WiFi, managed by a single group or company, often connected with twisted pair cables.

Metropolitan Area Network (MAN)

MANs connect multiple LANs across a city or campus. Faster communication is achieved using high-speed carriers like fiber optic cables.

Wide Area Network (WAN)

WANs connect large geographical areas, including countries or continents, using fiber optic cables or satellite uplinks. WANs allow communication between multiple smaller networks.

Summary

  • Three main types of networks: LAN, MAN, and WAN.
  • LAN – small, used in homes and offices.
  • MAN – medium, connects campuses or city-wide networks.
  • WAN – large, connects countries or global networks.
  • Networks can use wireless or wired connections.

Mobile Networks

A cellular network or mobile network is a radio network distributed over land areas called cells, each served by at least one fixed-location transceiver, known as a cell site or base station.

Key Points

  • Cells provide radio coverage over a wide area.
  • Allows communication between portable devices and fixed transceivers via base stations.

Advantages of Cellular Networks

  • Flexible with features of public and private networks.
  • Increased capacity.
  • Consumes less power.
  • Distributed over large coverage areas.
  • Reduces interference from other signals.

Generations of Cellular Networks

  • 1G – Voice-only analog service, max speed 2.4 kbps.
  • 2G – Digital service, call/text encryption, SMS/MMS, max speed 50 kbps.
  • 3G – Video calling, mobile internet, 2 Mbps stationary, 384 kbps moving.
  • 4G – High-speed mobile internet, peak 100s Mbps stationary, 10s Mbps moving.
  • 5G – Ultra high-speed, low latency, supports billions of devices and IoT.

Summary

  • Cellular networks are radio networks divided into cells.
  • Each generation (1G–5G) improves speed, capacity, and connectivity.
  • 5G enables faster streaming, reduced latency, and higher device density.

Wireless Network Technology

Wireless networks use radio waves to connect devices without cables. They are convenient for avoiding costly cabling and connecting equipment over distances.

Examples of Wireless Technology

  • Bluetooth – Short-range wireless, slower than WiFi, connects up to 8 devices, often for device-to-device transfers.
  • WiFi – Provides network connectivity via hotspots, frequency 2.4–5 GHz, speed depends on network load.
  • Hotspots – Areas where WiFi access is available (home, public spaces).

Summary

  • Wireless networks don’t use wires.
  • Bluetooth – simple setup, short-range, up to 8 devices.
  • WiFi – wireless internet access.
  • Hotspot – area with available WiFi connection.

Internet, Intranet, and Extranet

These are networks with different privacy levels:

  • Internet – Global network, full public access, uses TCP/IP over various media.
  • Intranet – Private network within an organization, sits behind a firewall.
  • Extranet – Intranet partially accessible to authorized outsiders via controlled access.

Summary

  • Three levels of privacy: Internet (public), Intranet (private), Extranet (authorized outsider access).

Transmission Media

Transmission media are pathways connecting devices on a network. Two main types exist: physical (wired) and wireless.

Physical Media (Guided)

  • Coaxial Cable – Copper core, insulated, shielded, high data capacity.
  • Twisted Pair – Two wires twisted together, types: Shielded (STP) and Unshielded (UTP).
  • Fibre Optic – Glass threads transmitting light signals, high bandwidth, minimal interference, very fast.

Wireless Media (Unguided)

  • Microwaves – Straight-line propagation, minimal atmospheric refraction.
  • Satellite – Uses radio waves to send/receive signals over long distances.
  • Infrared – Short-range, direct line-of-sight communication (e.g., remote controls).

Summary

  • Two transmission media types: guided (wired) and unguided (wireless).
  • Guided: coaxial, twisted pair, fibre optic.
  • Wireless: satellite, microwave, infrared.
  • Fastest connection is fibre optic.

Network Devices

Router

Analyzes data packets and determines if they remain on the same network or transfer to another network.

Network Switch

Centralizes communication among multiple connected devices in a LAN.

Modem

Modulator/Demodulator – converts analog signals to digital and vice versa, enabling internet connectivity.

Network Interface Card (NIC)

Hardware component that allows computers to connect to a network, wired or wireless.

Summary

  • Modem – converts analog and digital signals.
  • Network Switch – centralizes communication in a LAN.
  • Router – routes data packets between networks.
  • NIC – hardware to connect a computer to a network.

Web Technologies

World Wide Web (WWW)

A system of Internet servers supporting documents in HTML with hyperlinks, graphics, audio, and video.

HTTP

Hypertext Transfer Protocol – standard for web browsers and servers to communicate.

HTML

Markup language used to create web pages. Supports hyperlinks and formatting.

Web Pages and Websites

  • Web page – HTML document accessible via a browser.
  • Website – collection of web pages.
  • Web server – computer that serves web pages.
  • URL – global address of documents and resources on the web.

File Transfer Protocol (FTP)

Rules for communicating and transferring files over the Internet.

Web Browser

Application software for navigating the WWW. Examples: Google Chrome, Firefox, Opera.

Uploading and Downloading

  • Uploading – transferring files from your device to the internet.
  • Downloading – transferring files from the internet to your device.

Summary

  • WWW – system of servers supporting HTML documents.
  • HTTP – protocol standard for web communication.
  • HTML – language used to create web pages.
  • Webpage – single document; Website – collection of webpages.
  • Web server – delivers webpages. URL – global address of resources.
  • FTP – rules for transferring files over the internet.
  • Web browsers – Chrome, Firefox, Opera.
  • Uploading – device to server; Downloading – server to device.