A computer network is a group of connected devices that communicate with each other to share data and resources. It enables efficient communication and supports services like email, file sharing, and internet access.
Nodes are devices such as computers, mobiles, or printers that exchange data.
Routers and switches control and direct the flow of information.
Transmission media carries data between devices.
Wired media includes Ethernet and optical fiber cables.
Wireless media includes Wi-Fi, Bluetooth, and infrared.
A computer network operates by enabling devices to communicate and exchange data using a shared communication system. Each device in the network follows predefined rules to ensure that data is transmitted accurately, efficiently, and securely.
A network consists of nodes such as computers, servers, routers, and switches that send or receive data.
These nodes are connected through links, which may be wired (cables, optical fiber) or wireless (Wi-Fi, radio signals).
When data is sent, it is broken into small packets and transmitted across the network.
Protocols define how data packets are formatted, transmitted, received, and acknowledged.
Each device is identified by a unique IP address, which ensures data reaches the correct destination.
Network devices like switches and routers forward data packets along the best available path.
Security mechanisms, such as firewalls, monitor traffic and allow or block data based on security rules.
Types of Computer Network Architecture
Computer Network falls under these broad Categories:
Client-Server Architecture: Client-Server Architecture is a type of Computer Network Architecture in which Nodes can be Servers or Clients. Here, the server node can manage the Client Node Behaviour.
Peer-to-Peer Architecture: In P2P (Peer-to-Peer) Architecture, there is not any concept of a Central Server. Each device is free for working as either client or server.
Network Devices
1. Router
A Router is a networking device that connects multiple networks and directs data between them.
Connects local networks to the internet
Determines the best path for data packets
Uses IP addresses to forward data correctly
2. Switch
A Switch connects devices within the same network and manages internal data communication.
Connects computers, printers, and servers
Sends data only to the intended device
Improves network efficiency and performance
3. Hub
A Hub is a basic device that connects multiple devices in a network.
Broadcasts data to all connected devices
Does not filter or manage traffic
Less secure and less efficient than a switch
4. Bridge
A Bridge connects two network segments and filters traffic between them.
Reduces unnecessary data transmission
Improves network performance
Works using MAC addresses
5. Gateway
A Gateway connects two different networks that use different protocols.
Translates data between different systems
Enables communication between dissimilar networks
Commonly used to connect private networks to external networks
6. Access Point (AP)
An Access Point provides wireless connectivity to devices in a network.
Extends a wired network into Wi-Fi
Allows mobile devices to connect wirelessly
Improves network coverage area
7. Modem
A Modem converts digital data into signals suitable for transmission and vice versa.
Connects a home or office network to the ISP
Converts digital signals to analog and back
Enables internet access
8. Firewall
A Firewall is a security device that monitors and controls network traffic.
Blocks unauthorized access
Filters incoming and outgoing data
Protects networks from cyber threats
Goals and Uses of Computer Networks
Communication and Collaboration: Enable communication through email, messaging, video conferencing, and collaborative platforms.
Resource Sharing: Allow multiple users to share hardware, software, and data resources efficiently.
Data Access and Sharing: Provide easy access to stored data and allow information exchange between users and systems.
Internet and Cloud Access: Enable access to the Internet, online services, and cloud-based applications.
Cost Efficiency: Reduce operational and infrastructure costs through shared resources and centralized systems.
Reliability and Availability: Improve system reliability using backup paths and fault-tolerant mechanisms.
Scalability and Growth: Support easy expansion by adding new devices and services as demand increases.
Security and Control: Protect data and network resources using authentication, access control, and monitoring.
