BCOM CA FIT-4
4.1 Basics of Networking: LAN, WAN, WLAN, Internet –
Network Topologies (Star, Bus, Ring,
Mesh - conceptual)
LAN (Local Area Network)
· A network
connecting computers/devices within a small area (office, school, home).
· High
speed; uses cables (Ethernet) or Wi-Fi.
· Used for
sharing files, printers, apps within one building.
WAN (Wide Area Network)
· Spans a
large geographic area (cities, countries).
· Connects
multiple LANs via leased lines, fiber optics, satellites, etc.
· The
Internet is a global WAN.
WLAN (Wireless LAN)
· LAN using
Wi-Fi (IEEE 802.11); enables device mobility.
· Common in
homes, offices, campus hotspots.
Internet
· Interconnected
global network of millions of devices and networks.
· Uses
TCP/IP protocols; enables communication (email, web, streaming) worldwide.
Network Topologies – Conceptual Overview
· Each
device connects to a central hub/switch using its own cable.
· Data
passes through the hub.
· Advantages:
Easy fault isolation, simple add/remove devices, robust to individual link
failure.
· Disadvantage: Hub is a single point of failure; if it fails, entire network stops.
· All
devices connect to a common backbone cable.
· Data
travels along the cable; each device listens for its address.
· Advantages:
Simple, low cost, easy to implement in small networks.
· Disadvantages: Prone to data collisions; backbone failure disrupts all communication.
· Devices
connected in a closed loop (circle); each device has 2 neighbors.
· Data
travels in one direction (“token passing”), device passes data around the ring
until it reaches destination.
· Advantages:
Predictable data flow; simple management in small loops.
· Disadvantages: Failure of any one device/cable breaks the loop and stops communication; not easily scalable.
· Each
device has connections to every other device, forming a complex web.
· Can be
“full mesh” (all possible connections) or “partial mesh."
· Advantages:
Highly reliable; multiple paths—failure of one connection doesn’t affect the
network.
· Disadvantages:
Expensive; complex to install and maintain; used in backbone networks or
critical environments.
|
Topology |
Key Feature |
Pros |
Cons |
Typical Use |
|
Star |
Central hub |
Easy management; robust |
Hub failure stops network |
LANs (offices, labs) |
|
Bus |
Backbone
cable |
Simple,
low cost |
Collisions,
limited length |
Small, temporary networks |
|
Ring |
Closed loop |
Predictable flow |
Break = total loss |
Campus, MAN, legacy LANs |
|
Mesh |
Many
connections |
Reliability,
redundancy |
Cost,
complexity |
WANs, backbone, critical networks |
· LAN =
local, high speed; WAN = global, connects many LANs; WLAN = wireless LAN;
Internet = global network.
· Star is
common for modern LANs; bus/ring are less common today except in legacy
systems.
· Mesh used
for reliability, key in WANs and critical facilities.
· Topology
affects scalability, cost, fault tolerance, and ease of management.
4.2 Network Devices – Routers, Switches, and Modems
Introduction:
This
document explains the roles and applications of routers, switches, and modems,
with sample images for clear understanding.
1.
Router:
- Main Functions:
- Routes data between different
networks (LAN to WAN)
- Assigns local IP addresses
using DHCP
- Provides security features such
as firewalls and NAT
- Applications: Home Wi-Fi, Office Internet
gateway, Data centers
- Definition: A device connecting multiple
devices within a single network (LAN), forwarding data to the correct
device by MAC address.
- Main Functions:
- Reduces network collisions and improves
efficiency
- Applications: Office networks, Server rooms,
College labs
3. Modem:
- Main Functions:
- Connects digital devices to the
ISP network
- Enables home or remote Internet
access
- Applications: Broadband at home, Mobile
Internet, Remote workstations
Summary
Table
|
Device |
Main Role |
Key Applications |
|
Router |
Connect networks,
route data |
Home/Office internet,
Data centers |
|
Switch |
Connect LAN devices |
Office/College LAN, Server rooms |
|
Modem |
ISP access, data
modulation |
Home, remote/mobile
connectivity |
Client-Server
Architecture
Client-Server Architecture is a foundational concept in
computer networks and system design, widely used in modern applications such as
websites, databases, and cloud platforms. Here’s an exam-ready,
student-friendly summary:
What is Client-Server Architecture?
●
Definition:
●
Request-Response Model:
Clients communicate with servers using request-response protocols such as HTTP
(for web), SQL (for databases), etc.
●
Client:
The device or application that initiates communication (e.g., web browser,
email app, mobile app).
●
Server:
The powerful device or application providing services, such as:
o Web servers (e.g., Apache, Nginx)
o Database servers (e.g., MySQL,
Oracle)
o Email servers
●
Network:
Facilitates communication between client and server, usually over the Internet
or LAN.
|
Component |
Role |
Example Applications |
|
Client |
Requests data/services, provides user
interface |
Browsers, email clients, mobile apps |
|
Server |
Provides data/services, processes
requests |
Web hosting, email delivery, remote
databases |
● Web Services: Browsers request web pages from web servers.
●
Email: Email applications connect to
email servers to send and receive messages.
●
Database Management: Applications (clients) send data
queries to database servers.
● Enterprise Applications: CRM, ERP, and e-learning systems use client-server models for centralized management and multi-user access.
●
Cloud Computing: Resources and services hosted on
remote servers, accessible by clients worldwide.
Advantages of Client-Server Architecture
●
Centralized management and
security
●
Efficient data storage and
processing
●
Scalability: Easily add more clients or
increase server capacity
● Reliability and availability: Backup, redundancy, and load balancing can be managed on the server.
User (Client) → (Request) → Server
User (Client) ← (Response) ← Server
●
Multiple clients connect to a single server, which can
manage and respond to simultaneous requests.
This model is the backbone of modern IT, powering everything from websites and mobile apps to enterprise and cloud solutions.
4.3 Internet Fundamentals:
IP, DNS, URLs, Browsers, Search
Engines
● Definition: A set of rules governing the format and transmission of data across networks.
● IP Address: Unique numerical label (e.g., 192.168.1.1) assigned to every device on a network.
● Role: Identifies sender and receiver, enables routing data (packets) across networks.
● Types:
o IPv4: 32-bit, e.g., 134.201.250.155
o IPv6: 128-bit, e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334
● Definition: The "phonebook" of the Internet. Converts human-readable domain names (e.g., www.example.com) into IP addresses.
● Role: Makes web browsing user-friendly; for each site visited, browsers use DNS to find the corresponding IP address.
● How It Works:
a. User enters a website’s name in browser.
b. Browser queries DNS server.
c. DNS server returns the website’s IP address.
3. URLs (Uniform Resource Locators)
● Definition: Address of a resource on the Internet.
● Structure:
o Protocol: http://, https://
o Domain Name: www.example.com
o Path: /about
o Query: ?id=123
●
Example:
https://www.example.com/about?id=123
● Definition: Software applications used to access, view, and interact with websites and internet resources.
● Examples: Google Chrome, Mozilla Firefox, Microsoft Edge, Safari.
● Functions:
o Fetch and display web pages (HTML, CSS, JavaScript)
o Handle cookies, downloads, bookmarks
● Definition: Online tools for finding information on the Internet.
● Examples: Google, Bing, Yahoo, DuckDuckGo
● How They Work:
o Crawl and index web pages
o Rank results using algorithms (relevance, popularity, freshness)
o Display results for user queries
Summary Table
Term |
Role/Function |
Example |
|
IP Address |
Device identification; routing |
192.168.1.1 |
|
DNS |
Converts domain to IP |
|
|
URL |
Web resource address |
https://... |
|
Browser |
Accesses/displays websites |
Chrome, Edge |
|
Search Engine |
Finds online info |
Google, Bing |
4.4 E-Commerce Basics
Definition:
E-commerce (Electronic Commerce) is the buying and selling of goods and
services over the Internet. It includes electronic transactions, payments,
supply chain management, and online marketing.
|
Model |
Description |
Example(s) |
Typical Applications |
|
B2C |
Business to Consumer: Businesses sell directly to consumers |
Amazon, Flipkart, Myntra |
Online retail, ticket booking |
|
B2B |
Business to Business: Businesses sell products/services to other businesses |
Alibaba, Udaan, software vendors |
Wholesale, SaaS, bulk orders |
|
C2C |
Consumer to Consumer: Consumers sell to other consumers using a platform |
OLX, eBay, Craigslist |
Second-hand goods, auctions |
|
C2B |
Consumer to Business: Individuals offer products/services to businesses |
Freelancing (Fiverr, Upwork) |
Hiring freelancers, influencer marketing |
|
B2G |
Business to Government: Businesses sell to government agencies |
Government tenders, e-procurement |
Supplying IT, infrastructure |
|
G2C/G2B |
Government to Consumer/Business: Government provides services online |
Government portals, tax filing |
Public services, applications |
● Convenience: Buy/sell anytime, anywhere
● Wider Reach: Businesses and consumers can connect globally
● Efficiency: Faster transactions, automated supply chain, reduced paperwork
● Cost Savings: Less need for physical stores, low operational costs
● Growth Opportunities: Access to larger markets, easy scalability
● Digital Skills: Prepares students for IT-driven business and technology careers
Summary Table
|
Model |
Who Sells |
Who Buys |
Key Example |
|
B2C |
Business |
Consumer |
Amazon, Flipkart |
|
B2B |
Business |
Business |
Alibaba, Salesforce |
|
C2C |
Consumer |
Consumer |
OLX, eBay |
|
C2B |
Consumer |
Business |
Fiverr, Upwork |
|
B2G |
Business |
Government |
E-procurement |
|
G2C |
Government |
Consumer |
Passport, tax portals |
E-commerce is transforming the way business operates, creating new models for buying, selling, and providing services. Understanding these models is crucial for students pursuing careers in computer science, business, and technology.
----------4.4.1 Social Media in Business
What is Social Media in Business?
Social media refers to online platforms (like Facebook, Instagram, X, LinkedIn, YouTube, WhatsApp) where people create, share, and interact with digital content and communities. In business, these channels are powerful tools for marketing, communication, sales, and brand-building.
1. Brand Visibility
· Social media helps businesses reach millions of people quickly and globally.
· Regular online posting and engagement boost brand awareness and recognition.
2. Marketing & Advertising
· Targeted ads on platforms (Facebook, Instagram, etc.) reach specific demographics.
· Businesses can showcase products/services through creative content—text, images, videos, and stories.
3. Customer Engagement
· Instant messaging and comments foster direct communication, feedback, and relationship-building.
· Quick responses improve customer satisfaction and loyalty.
4. Lead Generation & Sales
· Businesses use social ads, promotions, and interactive posts to attract new customers and drive sales.
5. Content Creation
· Sharing valuable information, educational posts, entertainment, and promotional offers is a cost-effective way to build trust and attract audiences.
· User-generated content (reviews, testimonials, shares) increases reach and credibility.
6. Analytics & Feedback
· Platforms provide analytics to measure reach, engagement, and campaign success.
· Businesses can adjust strategies based on real-time data.
7. Influencer & Community Partnerships
· Collaboration with influencers increases brand exposure and credibility.
· Builds digital business skills and prepares for modern marketing jobs.
· Enables entrepreneurship: Students use social media to sell products/services, connect with buyers, and promote businesses cheaply.[6]
· Promotes personal branding for career opportunities.
· Provides direct access to industry trends and business networks.
|
Role |
Benefit to Business |
Example Platforms |
|
Brand Visibility |
Wider audience, recall |
Instagram, Facebook |
|
Customer Engagement |
Instant
feedback, loyalty |
WhatsApp,
Instagram |
|
Marketing & Sales |
Targeted ads, direct sales |
Facebook, LinkedIn |
|
Analytics/Tracking |
Measure
success, improve strategy |
Twitter,
YouTube |
|
Influencer Marketing |
Boost trust, expand reach |
Instagram, YouTube |
In
summary:
Social media is not just for personal use—it is essential for growing,
marketing, and managing any modern business. Learning to use it skillfully
prepares students for digital-age careers, opens paths for entrepreneurship,
and helps businesses thrive.
Wired (Ethernet, Fiber), Wireless
(Wi-Fi, Bluetooth)
· Definition: Uses copper cables (Cat5/Cat6)
for high-speed local area network (LAN) connections.
· Applications: Office
networks, desktops, switches, routers.
· Features: Reliable, stable, high bandwidth (up to 1 Gbps), low interference, physical cabling required.
· Definition: Uses glass/plastic fibers to
transmit data as light pulses for ultra-fast, long-range connections.
· Applications:
Backbones in enterprises, ISPs, data centers.
· Features: Extremely high speed (up to 100+ Gbps), long distance (km), immune to electromagnetic interference, expensive.
· More
stable, secure, and reliable
· Higher
speeds, lower latency
· Used for critical systems: banking, healthcare, large organizations
· Requires
cabling and installation
· Mobility limited (devices must be wired)
· Definition: Uses radio waves for wireless
LAN connectivity, commonly found in homes, offices, public areas.
· Applications: Laptops,
smartphones, tablets, smart devices.
· Features: Easy setup, good for mobility, speeds up to 50 Mbps-1 Gbps (latest Wi-Fi 6).
· Definition: Wireless Personal Area Network
(PAN) technology, using short-range radio waves.
· Applications:
Headsets, speakers, keyboards, fitness devices, file transfers.
· Features: Short range (~10m), low power, easy pairing and low data rate.
· Flexible
and highly mobile (no wires)
· Quick
installation, scales easily
· Used where mobility and ease of access matter: homes, smart devices, portable electronics
· More
prone to interference and security issues
· Slower speeds than wired; signal quality decreases with distance/barriers
|
Technology |
Medium |
Speed
(Typical) |
Reliability |
Range |
Common
Uses |
|
Ethernet |
Copper |
Up to 1
Gbps |
Very
High |
~100m |
Offices,
desktops |
|
Fiber |
Glass/Plastic |
10-100+
Gbps |
Highest |
>2km |
Backbone,
ISPs |
|
Wi-Fi |
Radio |
Up to 1
Gbps (Wi-Fi 6) |
Medium-High |
~50m |
Homes,
devices |
|
Bluetooth |
Radio |
1-3
Mbps |
Medium |
~10m |
Personal
gadgets |
Summary:
Wired communication is ideal for areas needing high reliability and speed
(Ethernet, fiber), while wireless (Wi-Fi, Bluetooth) is best for mobility and
convenience in personal and casual communications. Businesses and homes use
both, balancing performance and flexibility.
Bandwidth
& Speed Concepts (bps,Mbps,
Gbps)
Definition:
· Bandwidth is the maximum rate at which
data can be transmitted over a network. It determines how much data can be sent
in a given time.
· Speed refers to how fast data travels
from source to destination.
· bps (bits per second):
o
Basic unit of data transfer rate.
o
bps = 1 bit transmitted per second
· Kbps (Kilobits per second):
o
Kbps = 
bits per second
· Mbps (Megabits per second):
o
Mbps = 
bits per second
· Gbps (Gigabits per second):
o
Gbps = 
bits per second
|
Unit |
Full
Form |
Bits
per Second |
Example
Usage |
|
bps |
bits
per second |
1 |
Serial
communication |
|
Kbps |
kilobits/sec |
1,000 |
Early
modems, basic apps |
|
Mbps |
megabits/sec |
1,000,000 |
Home
broadband, Wi-Fi, streaming |
|
Gbps |
gigabits/sec |
1,000,000,000 |
Fiber
internet, data centers |
· Higher bandwidth and speed = more
data transmitted in less time (faster downloads, streaming, and web browsing).
· Used to
compare performance of network links, devices, and ISPs.
Example:
· A video
stream may require 
Mbps.
· Fiber
broadband can offer Gbps, which is 200x faster than that video
stream requirement.
Summary:
Bandwidth and speed, measured in bps, Mbps, and Gbps, are critical for
evaluating and comparing network performance in computers, smartphones, and all
online communication.
Comments
Post a Comment