CHAPTER 1 (NETWORKING CONCEPTS) NOTES
1. What is a Computer Network?
A computer network is a system of interconnected computers and devices that communicate with each other to
share resources, data, and applications.
Example: The Internet is the largest computer network in the world.
Key Points:
•
Enables communication between devices.
•
Helps in resource sharing (files, printers, etc.).
•
Requires networking hardware and software.
2. What is a Node?
A node is any device connected to a computer network, such as computers, printers, servers, or other networking
devices.
Example: A laptop connected to Wi-Fi is a node in a network.
Key Points:
•
Nodes communicate with each other.
•
Can be client or server.
3. What is a Server?
A server is a computer or system that provides resources, data, services, or programs to other computers (clients)
over a network.
Example: A web server hosts websites.
Key Points:
•
Provides services like file storage, emails, or applications.
•
Can be dedicated hardware or software.
4. Advantages of Computer Networking
•
Resource Sharing – Printers, files, and internet connections can be shared.
•
Improved Communication – Emails, messaging, and video conferencing.
•
Cost Efficiency – Reduces hardware and software costs.
•
Data Accessibility – Access data from different locations.
5. Disadvantages of Computer Networking
•
Security Issues – Risk of hacking, viruses, and data breaches.
•
Maintenance Costs – Requires regular updates and monitoring.
•
Dependency on Network – If the network fails, resources become inaccessible.
6. What is Video Conferencing?
Video conferencing is a technology that allows users to communicate via video and audio in real time over the
internet.
Example: Zoom, Google Meet, and Microsoft Teams.
Key Points:
•
Requires a webcam, microphone, and internet.
•
Used for remote meetings, online classes.
7. What is Intranet?
An intranet is a private network within an organization that allows employees to share information and resources.
Example: A company’s internal portal.
Key Points:
•
Restricted to organization members.
•
More secure than the internet.
8. What is Extranet?
An extranet is a private network that allows controlled access to external users like business partners.
Example: Supplier access to a company’s inventory system.
Key Points:
•
Extends intranet functionality to external users.
•
Requires authentication and security measures.
9. Difference between Intranet, Extranet, and Internet
Feature
Intranet
Extranet
Internet
Access Internal employees only Selected external users Open to the public
Security High
Usage
Moderate
Low
Internal communication Business collaboration Global information sharing
10. What is Bluetooth?
Bluetooth is a wireless technology that allows short-range communication between devices.
Example: Wireless headphones connecting to a smartphone.
Key Points:
•
Uses radio waves.
•
Limited range (typically up to 10 meters).
11. What is a Protocol?
A protocol is a set of rules that govern data communication over a network.
Example: TCP/IP, HTTP, FTP.
Key Points:
•
Ensures reliable communication.
•
Standardized rules for data transmission.
12. Networking Components
•
Network Card (NIC): Allows a computer to connect to a network.
•
Networking Cable: Physical medium for data transfer (Ethernet cable).
•
Modem: Converts digital signals to analog and vice versa.
•
Hub: Connects multiple devices but does not manage data flow.
•
Switch: Similar to a hub but directs data to the correct device.
•
Router: Directs data packets between networks.
13. Difference between Router, Switch, and Hub
Feature
Function
Router
Switch
Hub
Connects different networks Manages data flow Broadcasts data to all devices
Data Filtering Yes
Yes
No
Efficiency
Moderate
Low
High
14. Wireless Networking
•
Wireless Network Card: Connects a computer to Wi-Fi.
•
Access Points: Extend wireless coverage in a network.
•
Wi-Fi: Wireless technology for high-speed internet.
15. Types of Computer Networks
•
PAN (Personal Area Network): Smallest network for personal devices (Bluetooth, hotspot).
•
LAN (Local Area Network): Covers a small geographical area (Office, school network).
•
WAN (Wide Area Network): Covers large geographical areas (Internet).
16. Network Architecture
•
Client-Server Architecture: Centralized control, with servers managing data.
•
Peer-to-Peer Architecture: All devices share equal responsibility.
Difference:
Feature Client-Server Peer-to-Peer
Control Centralized
Decentralized
Cost
Lower
Higher
Security More secure Less secure
17. Network Topology
•
Physical Topology: Actual physical layout of the network.
•
Logical Topology: The way data flows in a network.
Types:
Topology Description
Bus
Single backbone cable, data travels in both directions.
Star
Devices connect to a central hub/switch.
Ring
Data flows in a circular path.
Tree
Combination of star and bus topology.
Mesh
Every node connects to every other node.
18. File Sharing & Security
•
Need for Sharing Drive: Allows multiple users to access files.
•
Accessing Shared Files: Navigate to the network location and open files.
•
Network Icon: Indicates network connection status.
•
Network Security: Protects network resources from threats.
•
Login Security: Uses authentication (username/password).
•
Rights Security: Controls user permissions.
Difference between Login and Rights Security:
Feature Login Security
Rights Security
Purpose Verifies identity
Assigns access permissions
Example Username & Password Read, Write, Execute rights
Case Studies with Questions for practices
Case Study 1: Implementing Intranet in an Organization XYZ Corp. decided to implement an intranet for internal
communication and resource sharing. Employees can access company policies, announcements, and shared files.
Questions:
1. What is an intranet?
2. How does an intranet benefit an organization?
3. How does it differ from the internet?
Answers:
1. A private network for internal organizational use.
2. Enhances communication, file sharing, and security.
3. The internet is public; an intranet is restricted to members.
Case Study 2: Security Issues in Networking
ABC Ltd. faced a major security breach when an unauthorized user accessed confidential data. The company had
weak password policies and no firewall protection.
Questions:
1. What network security measures could have prevented the breach?
2. What is the importance of login security?
3. What is the role of a firewall in network security?
Case Study 3: Video Conferencing in Education
Due to the COVID-19 pandemic, schools adopted online learning. Students and teachers used video conferencing
tools like Zoom and Google Meet to conduct classes.
Questions:
1. What is video conferencing?
2. What are the advantages of using video conferencing in education?
3. Name two popular video conferencing tools.
Case Study 4: Differentiating Network Topologies
A company is setting up a network for its office and is considering bus, star, and ring topologies. The IT department
must decide which topology best suits their needs.
Questions:
1. What are the advantages of using a star topology?
2. How does a bus topology differ from a ring topology?
3. Which topology is best for a small office and why?
Case Study 5: Understanding Client-Server Architecture
A bank uses a client-server network where all transactions are processed on a central server. Customers access their
accounts through client computers.
Questions:
1. What is client-server architecture?
2. How does a server differ from a client?
3. Why is client-server architecture beneficial for a bank?
differences between Ring Topology and Star Topology :
Feature
Ring Topology
Star Topology
Structure
All devices are connected in a circular
manner, forming a ring.
All devices are connected to a central hub or switch.
Data
Transmission
Data travels in one direction (unidirectional) Data is sent from the central hub/switch to the
or both directions (bidirectional) in a loop. intended device.
If one device or connection fails, the entire
Failure Impact
network may stop working.
If one device fails, the network continues to
function, but if the central hub fails, the whole
network is affected.
differences between Bus Topology and Tree Topology for Class 8 students:
Feature
Bus Topology
Tree Topology
Structure
All devices are connected to a single
central cable (backbone).
It has a hierarchical structure where multiple star
networks are connected to a central backbone cable.
Failure
Impact
If the central backbone cable fails, the
entire network stops working.
If a branch fails, only that part is affected, but if the
backbone cable fails, the whole network is affected.
Scalability
Difficult to expand as adding more
devices can slow down the network.
Easier to expand by adding more star networks to the
main cable.
differences between Mesh Topology, Star Topology, and Bus Topology for Class 8 students:
Feature
Mesh Topology
Star Topology
Bus Topology
Structure
Every device is connected to every other All devices are connected All devices are connected to a
device.
to a central hub or switch. single central cable (backbone).
Failure
Impact
If one connection fails, the network
continues to work because multiple
paths exist.
If the central hub fails, the If the backbone cable fails, the
entire network is affected. entire network stops working.
Cost and
Setup
Expensive and difficult to set up due to
many connections.
Moderate cost and easy to Low cost and easy to set up but
set up with fewer cables. limited scalability.
differences between LAN (Local Area Network), MAN (Metropolitan Area Network), and WAN (Wide Area
Network) for Class 8 students:
Feature
LAN (Local Area Network)
MAN (Metropolitan Area
Network)
WAN (Wide Area Network)
Coverage
Area
Covers a small area like a
home, school, or office
building.
Covers a larger area, typically a
city or a large campus.
Covers a vast area, such as a country
or even globally.
Speed
High speed with fast data
transfer rates.
Moderate speed, slower than
LAN but faster than WAN.
Slower speeds compared to LAN and
MAN due to long-distance
transmission.
Cost
Moderate cost, as it requires
Relatively low cost to set up
equipment for city-wide
and maintain.
coverage.
High cost to set up and maintain due
to large-scale infrastructure.
What is Point to Point Topology ?
Point-to-Point Topology is a type of network topology where two devices are directly connected to each other using
a single communication link. It is one of the simplest network configurations, often used to connect two locations or
devices that need to communicate with each other directly.
Key Points:
•
Direct Connection: Only two devices (like computers, routers, or switches) are connected in a point-to-point
setup.
•
No Intermediate Devices: There are no hubs, switches, or routers involved; just a single connection
between two devices.
•
Usage: It’s commonly used for dedicated connections like a leased line between two offices or devices that
need direct communication.
Example:
•
Connecting two computers via a crossover cable or setting up a dedicated link between two routers.
Advantages:
•
Simple Setup: Easy to install and configure.
•
Stable and Reliable: Since there are only two devices involved, there's less chance of network failure.
Disadvantages:
•
Limited Scalability: Only two devices can be connected, so it's not suitable for large networks.
For any query email to deeepeshsharma@dpsi.ac.in