9th Computer Science Unit 3 Networks Notes

Unit No. 3 Networks of Class 9th Notes

Defining Computer Network A computer network is a collection of interconnected devices, such as computers, servers, printers, and other peripherals, that can communicate and share resources with each other. Networks can be local (LAN) or wide (WAN) and are crucial for enabling data sharing, collaboration, and efficient communication between users.

Describing Physical Structure of a Network The physical structure of a network refers to the arrangement of devices and the medium used for communication. It can be represented as a topology, such as a star, bus, ring, or mesh. Devices are connected through cables (like Ethernet) or wirelessly (like Wi-Fi).

Understanding the Need for Establishing a Computer Network Computer networks facilitate resource sharing, data transfer, and communication, improving efficiency and productivity. They enable centralized management, cost savings through resource sharing, and seamless access to information and services.

Long Question Answers of Unit 3 Networks

MCQ’s of Unit Unit 3 Networks

Short Question Answers of Unit Unit 3 Networks

• Chapter No.1 Introduction to Biology
• Chapter No. 2 Solving a Biological Problem
• Chapter No.3 Biodiversity
• Chapter No.4 Cells and Tissues
• Chapter No.5 Cell Cycle

Defining Client and Server In a client-server model, a client is a user device that requests services or resources from a central server. The server provides those services, processes requests, and manages resources for multiple clients.

Basics of Communication

Sender and Receiver The sender is the source of the message, while the receiver is the destination that receives the message.

Message The message is the information or data sent from the sender to the receiver.

Protocol A protocol is a set of rules and conventions that govern how data is transmitted and received between devices. It ensures smooth communication and error handling.

Transmission Medium The transmission medium is the physical path or channel through which data is transmitted, such as cables, fiber optics, or wireless signals.

Understanding Network Models

Defining TCP/IP TCP/IP (Transmission Control Protocol/Internet Protocol) is the foundational protocol suite used in the internet and most modern networks. It defines how data is packetized, transmitted, addressed, routed, and received.

Describing Functions of TCP/IP Layers TCP/IP is organized into four layers – Application, Transport, Internet, and Link. Each layer has specific functions, such as data formatting, error detection, addressing, and routing.

Basics of Data Communications

Importance of Addressing in Data Communication Addressing enables proper identification of sender and recipient devices, ensuring that data reaches the intended destination.

Addressing in Telephone and Postal Services In telephone addressing, phone numbers uniquely identify users, while in postal services, addresses help deliver mail to specific locations.

Request/Response Mechanism of the Internet The request/response mechanism allows clients to send requests (e.g., HTTP requests) to servers, and servers respond with the requested data (e.g., web pages).

Understanding IP Addressing IP (Internet Protocol) addressing is a numerical label assigned to each device connected to a network. It enables proper routing of data across the internet.

Protocols in TCP/IP Suite

Understanding FTP, HTTP, and SMTP Protocols FTP (File Transfer Protocol) is used for file transfer, HTTP (Hypertext Transfer Protocol) for web browsing, and SMTP (Simple Mail Transfer Protocol) for email communication.

Understanding the Need for Addressing

Importance of Addressing in Data Communication Addressing ensures data reaches the intended destination, preventing data loss and ensuring efficient communication.

Addressing in Telephone and Postal Services In telephone and postal services, addressing is essential to identify and deliver messages to specific recipients.

Understanding HTTP Requests and their Responses

Differentiating IPv4 and IPv6 IPv4 and IPv6 are two versions of the Internet Protocol. IPv4 uses 32-bit addresses, while IPv6 uses 128-bit addresses, providing a vast address space to support the growing number of connected devices.

Routing

Functions of a Router A router is a networking device responsible for forwarding data packets between networks. It determines the best path for data transmission to reach the intended destination.