Key facts

  • IPv4 uses 32-bit addresses and provides about 4.3 billion unique addresses;
  • The World Wide Web is an application-layer system of interlinked hypertext documents invented by Tim Berners-Lee at CERN in 1989.
  • 5G offers theoretical peak speed up to 20 Gbps, a 1 millisecond user-plane latency target for low-latency use cases and support for 1 million devices...

Key Points at a Glance

  1. 1

    A computer network is a group of interconnected computers and devices that share data, services and resources through agreed communication rules.

  2. 2

    Network coverage is commonly classified as PAN, LAN, MAN and WAN; the Internet is the largest WAN.

  3. 3

    IPv4 uses 32-bit addresses and provides about 4.3 billion unique addresses; the IANA free pool was depleted in 2011, so IPv6 uses 128-bit addresses to solve address exhaustion.

  4. 4

    TCP/IP is the foundation of Internet communication: TCP supports reliable delivery, while IP handles addressing and routing.

  5. 5

    DNS translates domain names such as google.com into IP addresses, so it is often called the phone book of the Internet.

  6. 6

    The World Wide Web is an application-layer system of interlinked hypertext documents invented by Tim Berners-Lee at CERN in 1989.

  7. 7

    5G offers theoretical peak speed up to 20 Gbps, a 1 millisecond user-plane latency target for low-latency use cases and support for 1 million devices per km2.

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Network Meaning and Classification

A computer network connects two or more computers or digital devices so that they can exchange data and share resources. The shared resource may be a file, printer, database, Internet connection, server application or communication service. For an objective exam, the core point is simple: a network is not only hardware cables or Wi-Fi signals; it is the combination of connected devices, communication media, addresses and protocols that allow data to move correctly.

Networks are often classified by geographical coverage. A Personal Area Network covers a very small area, roughly around 10 metres, such as Bluetooth devices around one user. A Local Area Network covers a room, building or campus, such as a school computer lab or office Wi-Fi. A Metropolitan Area Network covers a city-level area, such as city-wide cable or wireless infrastructure. A Wide Area Network spans a country or the globe; the Internet is the largest and most familiar WAN.

Remember this distinction: PAN, LAN, MAN and WAN are coverage categories, not separate technologies.

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