Types of network

• A PAN is a network used for communication among personal devices like smartphones, tablets, and laptops within a short range, typically within a person's workspace or home.
• A LAN is a network that connects computers and devices within a limited area such as a home, office, or school. LANs are used for sharing resources like files, printers, and internet access among connected devices.
• A WAN is a network that spans a large geographical area, connecting LANs and other networks across cities, countries, or even continents. WANs enable communication between devices over long distances, often using public or private networks.
• In a client-server network model, multiple client devices (such as computers, smartphones, or tablets) are connected to a central server. The server provides resources, services, and data to the clients upon request. Clients rely on the server for accessing files, applications, or other network resources, while the server manages and controls these resources centrally. This architecture allows for efficient resource sharing, centralized management, and improved security within the network.
• In a peer-to-peer (P2P) network, individual devices, called peers, communicate and share resources directly with one another without the need for a central server. Peers act both as clients and servers, contributing resources like files or bandwidth while also accessing resources shared by other peers. P2P networks are decentralised, enabling efficient resource sharing and collaboration among devices without relying on a single point of control.
• A server is a program on a computer that shares resources with, or provides services to, any authorised client. Most servers will run 24 hours a day, 7 days a week, so that a client can send a request for resources at any time.
• There are many types of server:

  • File servers store and provide files.
  • Web servers store and provide webpages.
  • Email servers store and forward emails. Some email servers filter out spam.
  • Database servers store databases, run queries, and allow data to be manipulated.
  • Print servers provide printing services across the network and manage print queues.
• In large organisations, servers will usually run on high-powered dedicated computers that are able to handle a lot of requests at any one time. In smaller organisations, multiple servers may run on a single computer system.
• A client sends a request to the server. The server processes the request and then sends a response back to the client. For example, when you want to view a webpage, you will use a web browser (which is a web client). The browser will request the page from a web server. The server will send the page back to the browser and the page will be displayed.
• In a peer-to-peer network, there are no central servers. Every computer can be configured to share its resources. This can involve sharing files (e.g. games, movies, and music), software, processing power, or internet bandwidth. Peers can also share hardware such as printers or optical disc drives.
• Client-server networks - advantages:

  • Centralized management and control of resources.
  • Enhanced security and easier data backup.
  • Scalability for adding more clients and resources.
  • Efficient utilization of network resources.
• Client-server networks - disadvantages:

  • Single point of failure with the server.
  • Higher initial setup and maintenance costs.
  • Dependency on the server for resource access.
  • Potential network congestion due to centralized traffic.
• Peer-to-peer networks - advantages:

  • Decentralized architecture with no single point of failure.
  • Cost-effective setup and scalability.
  • Efficient resource sharing among peers.
  • Flexibility and autonomy for individual devices.
• Peer-to-peer networks - disadvantages:

  • Security risks with direct peer-to-peer connections.
  • Limited network management capabilities.
  • Potential for slower performance in larger networks.
  • Lack of centralised control for resource allocation.