Understanding Computer Networks

NETWORK

  • Definition: A network is a group of two or more computers linked together to facilitate communication and resource sharing, such as printers, modems, plotters, and hard drives.

    • This can involve two computers on a desk or thousands across the globe, as exemplified by the Internet.

    • Computers that are not part of a network are referred to as stand-alone computers.

    • Transfer of Data: Data on a stand-alone system must be transferred via secondary storage media to be utilized by another device.

TYPES OF NETWORKS

  • Overview: The primary types of computer networks are as follows:

    1. Local Area Networks (LANs)

    2. Metropolitan Area Networks (MANs)

    3. Wide Area Networks (WANs)

LOCAL AREA NETWORK (LAN)

  • Definition: A LAN is a group of microcomputers or workstations connected at a single location, such as a school or office block, for the purpose of information exchange.

  • Characteristics:

    • Computers in a LAN are generally connected via cables.

    • Each computer can function both as an independent unit and as a workstation accessing information from a central server.

  • Server: A server is a computer that manages software allowing the client computers on the network to communicate and share resources.

  • Shared Devices: Commonly shared devices on a LAN include:

    • Hard drives

    • Disk drives

    • Printers

    • Fax machines

    • Scanners

    • Modems

  • Modem: A modem is a device that converts signals between analog and digital formats.

    • Functionality: Digital signals sent by a computer must be converted to analog signals to be transmitted through an analog telephone line. Upon reaching the destination, they're converted back to digital format.

Advantages of LAN

  1. Sharing Hardware: Devices like printers can be shared among users.

  2. Storage Sharing: Storage mediums can also be shared.

  3. Software Sharing: Users can share software and data files.

  4. Cost Efficiency: It is cheaper to purchase one software copy and pay for a license than to buy separate software packages for each machine.

  5. Collaborative Working: Multiple users can collaborate on a single document.

  6. Communication: Users can communicate via email, enhancing connectivity.

Disadvantages of LAN

  1. High Setup Costs: Initial configuration and setup of a network can be expensive.

  2. Data Corruption Risk: Increased user access raises the risk of data corruption.

  3. Virus Spread: Higher risks of viruses due to easier transmission between connected computers on the network.

  4. Server Dependency: If the server fails, it affects the entire network's functionality.

  5. Maintenance Demands: Networks may require a dedicated network administrator for maintenance, translating to additional costs.

METROPOLITAN AREA NETWORK (MAN)

  • Definition: A MAN is a high-speed network that connects multiple LANs within a metropolitan area, such as a city or town.

  • Functionality: Handles a significant amount of communication activity across the region.

  • Coverage: Typically encompasses one or more LANs, but it covers a smaller geographic area than a WAN.

WIDE AREA NETWORK (WAN)

  • Definition: A WAN is a network that extends over a large geographic area such as a city, country, or globally.

  • Configuration: Utilizes various communication channels, including telephone lines, cables, and radio waves.

  • Structure: A WAN can consist of a single large network or multiple LANs interconnected.

  • Example: The Internet is the largest example of a WAN.

PERSONAL AREA NETWORK (PAN)

  • Definition: A PAN is a network that connects computers and devices within the range of an individual person.

  • Typical Range: Generally operates within a range of approximately 10 meters (33 feet).

  • Components: A Personal Area Network might involve:

    • Computers

    • Phones

    • Tablets

    • Printers

    • Personal Digital Assistants (PDAs)

    • Other entertainment devices like speakers and gaming consoles.

CHECK YOUR PROGRESS

  1. What is a modem?

    • A modem is a device that converts signals between analog and digital formats.

  2. What is the name given to a network that links several buildings in the same general location (e.g., cities and towns)?

    • This is referred to as a Metropolitan Area Network (MAN).

  3. A network that spans a nation or the world, like the Internet is called a _______________.

    • Answer: Wide Area Network (WAN)

  4. Allan runs a business from home and employs three people to help him with his work. He wants each of them to have access to a computer plus a central printer and fax machine.

    • Answer: Local Area Network (LAN)

  5. A multinational company wants its employees in four countries to be able to communicate with each other and access a central file server with clients’ records.

    • Answer: Wide Area Network (WAN)

  6. A large department store rents two blocks, partly for the store and partly for its offices. All computers and terminals have to be connected so that staff have access to the most up-to-date sales records.

    • Answer: Local Area Network (LAN)