A network is a system that connects multiple devices, such as computers, servers, smartphones, and printers, allowing them to communicate and share resources, data, and services.
Data Communications Networks are systems that enable the transmission of data between devices, such as computers, smartphones, servers, and other connected hardware.
- These networks allow data to be shared, processed, and communicated efficiently over various distances, from short-range connections within an office building to worldwide connectivity over the internet.
Components of a Network
Key components of a network include:
- Hub
- Switches
- Router
- Modem
- Cable and connectors
- Network interface card
1.) Hub:
A simple networking device that connects multiple computers in a network, typically within a LAN is called Hub.
- It receives data from one device and broadcasts it to all other devices connected to the hub.
- Hubs operate at the physical layer of the OSI model, meaning they don’t distinguish between devices—they simply pass data along to all connected devices.
- Less efficient and often replaced by switches in modern networks.
2.) Switch:
A switch is a more intelligent networking device than a hub. It operates at the Data Link Layer (Layer 2) and forwards data only to the device (or port) that is intended to receive it, based on the MAC (Media Access Control) address.
- Sends data only to the specific device that needs it.
- Supports Full-Duplex Communication.
- Unlike hubs, switches reduce network traffic and collisions by sending data to only the required port.
Example:
A switch connecting computers, printers, and servers in an office LAN.
3.) Router:
A router is a device that forwards data packets between computer networks, typically between a local network (LAN) and the internet (WAN).
- It operates at the Network Layer (Layer 3) of the OSI model and uses IP addresses to route data to its destination.
- Routers work at the network layer and determine the best path for data to travel to its destination. They enable communication between LANs and connect networks to the internet.
- Routers assign IP addresses to devices, making them essential for managing network traffic and providing internet connectivity.
4.) Modem:
A modem (short for modulator-demodulator) is a device that converts digital data from a computer into analog signals for transmission over telephone lines, and vice versa.
- It enables internet access by modulating and demodulating the data.
- Modems allow devices within a LAN to connect to the internet by enabling the transfer of data over broadband or dial-up connections.
5.) Cables and Connectors:
Cables and connectors are the physical mediums used to transmit data between networking devices.
- They can include twisted pair cables, coaxial cables, fiber-optic cables, and others, each having its own characteristics and uses.
- Connectors, such as RJ45 connectors for Ethernet cables, link cables to devices, enabling the physical connection needed for data transfer.
6.) Network Interface Card (NIC):
A Network Interface Card (NIC) is a hardware component that allows a device (such as a computer or printer) to connect to a network.
- It provides the necessary interface to connect to both wired and wireless networks.
- NICs have a unique MAC address and allow devices to send and receive data over a LAN or other networks.
- NICs can be wired (Ethernet) or wireless (Wi-Fi), depending on the network type.
Example:
The NIC in a laptop connects it to Wi-Fi or Ethernet, allowing communication with other devices.
