Networks

  • Networks are systems of interconnected computers, devices or operations that enable data exchange.
  • There are different types of networks: Local Area Networks (LANs), Wide Area Networks (WANs), Metropolitan Area Networks (MANs), Personal Area Networks (PANs), and Virtual Private Networks (VPNs).
  • LAN connects nearby devices, typically in the same building, while WAN spans greater geographical areas, connecting devices across cities, countries, or even continents.
  • MAN ties together networks within a specific city or metropolitan area. PAN commonly used for devices physically close to a person, such as smartphones and laptops.
  • VPN is a secure method of connecting to a private network from a remote location through the internet.
  • Networks can be personal (used by one individual) or shared (used by multiple individuals).
  • Various protocols are employed for network communication, including TCP/IP, HTTP/HTTPS, FTP, SMTP, and DHCP.
  • The main purpose of protocols is to set the rules for data exchange over networks. They determine the type of error checking, data compression, and how the sending device will indicate that it has finished sending a message.
  • Network topologies illustrate how devices/hosts are connected in a network. The common types are bus, ring, star, mesh, and hybrid. Each has its own functionalities, advantages, and disadvantages.
  • A network can either be wired or wireless, whereby wired networks often employ Ethernet cables, and wireless networks use Wi-Fi.
  • Networking hardware includes routers, switches, and hubs. Routers direct data, switches connect devices on a network, and hubs relay data to all devices on a network.
  • TCP/IP protocol stack consists of five layers: physical, data link, network, transport, and application. Each layer provides different services related to data transmission.
  • The OSI Model is another architectural model having seven layers: physical, data link, network, transport, session, presentation, and application.
  • The reliable transmission of data is critical in a network. Techniques include the use of parity bits, checksums and automatic repeat request (ARQ).
  • Security in networks is crucial. Techniques to offer security include the use of firewalls, secure sockets layer (SSL), login/passwords, and encryption techniques.