Lecture 01
Computer Networks
A computer network is a network of two or more devices interconnected to share resources and exchange information.
These devices can include computers, servers, printers, and other hardware. Networks allow for the efficient exchange of data, enabling various applications such as email, file sharing, and internet browsing.
Basic Terminologies of Computer Networks
Network: A group of connected computers and devices that can communicate and share data with each other.
Node: Any device that can send, receive, or forward data in a network. This includes laptops, mobiles, printers, earbuds, servers, etc.
Networking Devices: Devices that manage and support networking functions. This includes routers, switches, hubs, and access points.
Transmission Media: The physical or wireless medium through which data travels between devices.
Wired media: Ethernet cables, optical fiber.
Wireless media: Wi-Fi, Bluetooth, infrared
Service Provider Networks: Networks offered by external providers that allow users or organizations to lease network access and capabilities. This includes internet providers, mobile carriers, etc.
How Does a Computer Network Work
Basics building blocks of a Computer network are Nodes and Links.
A Network Node can be illustrated as Equipment for Data Communication like a Modem, Router, etc., or Equipment of a Data Terminal like connecting two computers or more.
Link in Computer Networks can be defined as wires or cables or free space of wireless networks (as shown in the below diagram) The working of Computer Networks can be simply defined as rules or protocols which help in sending and receiving data via the links which allow Computer networks to communicate.
Each device has an IP Address, that helps in identifying the device.
A firewall is a network security device either hardware or software-based which monitors all incoming and outgoing traffic and based on a defined set of security rules it accepts, rejects, or drops that specific traffic.
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.