What is the Internet?
The Internet is a global network of computers connected to share information, data, and resources. It allows people to communicate, search for information, watch videos, shop online, and much more.
Example:
When you use WhatsApp to message your friend or search for answers on Google, you’re using the Internet.
Features of the Internet
| Feature | Explanation | Example |
|---|---|---|
| Communication | Helps people communicate through emails, chats, and video calls. | Sending a video call on WhatsApp. |
| Information | Provides access to a huge amount of information. | Searching for a recipe on Google. |
| Entertainment | Watch movies, listen to music, and play games online. | Streaming a movie on Netflix. |
| E-commerce | Buy and sell products online. | Ordering clothes on Amazon. |
| Online Services | Access banking, learning, and government services. | Paying your electricity bill online. |
| Social Networking | Connect with people and share posts. | Posting pictures on Instagram. |
| Data Sharing | Share files and documents with others. | Sending a document via email. |
What is Web Browsing?
Web browsing means visiting different websites on the internet. We do this using a tool called a web browser (like Google Chrome, Firefox, or Safari).
How It Works:
- Open Browser: First, open the browser on your computer or phone.
- Search or Enter Website: Type the name of a website (like www.google.com) or search for information.
- View the Website: The browser shows the website with text, pictures, or videos.
Example:
If you type www.tutorialnexa.in, you will see the website with study materials and other information.
What is Search Engine?
A search engine is a tool on the internet that helps you find information quickly. You type a word or question (called a keyword) into the search box, and the search engine shows you a list of related websites.
How It Works:
- Enter Keyword: Type what you are looking for (like “weather today”).
- Search Results: The search engine shows a list of websites with the information you need.
- Click: You click on a website to read more.
Examples of Search Engines:
- Google: The most popular search engine
- Bing: Created by Microsoft
- Yahoo: Another search engine used by many people
- DuckDuckGo: Focuses on user privacy
- Baidu: Popular in China
What is E-mail (Electronic Mail)?
E-mail is a way to send and receive messages over the internet. It allows you to send text, images, files, and documents to one or more people instantly. To use e-mail, you need an e-mail address (like example@gmail.com) and an internet connection.
Advantages of E-mail:
| Advantages | Description |
|---|---|
| Fast and Instant | Messages are delivered instantly across the world. |
| Cost-effective | Sending an e-mail is free, requiring only an internet connection. |
| Attachments | You can send documents, images, and videos as attachments. |
| Environment-Friendly | Reduces paper usage by sending digital documents. |
| Communication Record | Keeps a record of sent and received messages. |
Disadvantages of E-mail:
| Disadvantages | Description |
|---|---|
| Spam and Junk | Unwanted e-mails can flood your inbox. |
| Security Risks | Risk of hacking and phishing attacks. |
| Internet Dependency | Requires an internet connection to send or receive messages. |
| Miscommunication | Messages may be misunderstood due to lack of tone or gestures. |
| Limited Attachment Size | There are limits to the size of files you can send. |
What is difference Between E-mail and Traditional Mail?
| Feature | E-mail (Electronic Mail) | Traditional Mail (Postal Mail) |
|---|---|---|
| Speed | Instant delivery within seconds | Takes days or weeks to deliver |
| Cost | Free or minimal internet charges | Requires postage stamps and delivery charges |
| Delivery Method | Sent over the internet | Delivered by postal workers |
| Attachment | Can send files, documents, images, and videos | Physical documents or parcels only |
| Accessibility | Accessible anytime through internet-enabled devices | Requires a physical address to receive |
| Security | Risk of hacking and phishing | Risk of loss or damage during transit |
| Environmental Impact | Eco-friendly, reduces paper usage | Consumes paper and other physical materials |
| Communication Record | Automatic record storage in e-mail accounts | Needs physical storage for letters |
| Formal Use | Commonly used for business and official communication | Still used for formal letters and legal documents |
What is Computer Network?
A computer network is a group of computers and devices connected to share data, resources, and information. These connections can be wired (using cables) or wireless (using Wi-Fi).
Advantages of Computer Networks:
| Advantages | Description |
|---|---|
| Resource Sharing | Devices like printers and storage can be shared by multiple users. |
| Data Sharing | Easy and fast sharing of files and information. |
| Communication | Users can communicate through e-mails, messages, and video calls. |
| Cost-Efficiency | Reduces the cost by sharing hardware and software resources. |
| Centralized Data Management | Information can be managed and backed up centrally. |
| Remote Access | Users can access the network from different locations. |
Disadvantages of Computer Networks:
| Disadvantages | Description |
|---|---|
| Security Risks | Risk of data theft and hacking if not properly secured. |
| Cost of Setup | Setting up a large network can be expensive. |
| Maintenance Issues | Requires regular maintenance and technical expertise. |
| Network Failure | If the network fails, communication and resource sharing are disrupted. |
| Virus Spread | Viruses and malware can quickly spread across connected systems. |
What is Transmission Media?
Transmission media is the path through which data travels from one computer to another in a network. It acts like a road for data to move.
Types of Transmission Media:
There are two types:
- Bounded Media (Wired Media)
- Unbounded Media (Wireless Media)
1. Bounded Media (Wired Media):
Bounded media uses physical wires or cables to send data.
Examples:
| Type | Description | Example |
|---|---|---|
| Twisted Pair Cable | Two copper wires twisted together to reduce interference | Used in telephone lines |
| Coaxial Cable | A single copper wire with layers for protection | Used in cable TV |
| Fiber Optic Cable | Thin glass or plastic wires that carry data as light signals | Used for high-speed internet |
Advantages:
- High security
- Faster data transfer
Disadvantages:
- Difficult to install over long distances
- Expensive for fiber optic cables
2. Unbounded Media (Wireless Media):
Unbounded media does not use wires. Data is sent through the air.
Examples:
| Type | Description | Example |
|---|---|---|
| Radio Waves | Used for communication over short distances | Wi-Fi and FM Radio |
| Microwaves | Used for long-distance communication | Satellite communication |
| Infrared | Used for very short distances | Remote controls for TVs |
Advantages:
- Easy to set up
- No need for physical cables
Disadvantages:
- Less secure
- Can be affected by weather or interference
Simple Memory Trick:
- Bounded Media: Think “Bounded = Bound with Wires”
- Unbounded Media: Think “Unbounded = Unbound, No Wires”
What is Guided Media and Unguided Media?
Transmission media is divided into two types: Guided Media and Unguided Media. These are used to transfer data in a computer network.
1. Guided Media (Wired Media):
Guided media uses physical cables or wires to transfer data.
Examples:
- Twisted Pair Cable: Used in telephone lines
- Coaxial Cable: Used in cable TV
- Fiber Optic Cable: Used for high-speed internet
Key Features:
- Data travels inside wires.
- Suitable for shorter and controlled environments.
2. Unguided Media (Wireless Media):
Unguided media does not use wires. Data is sent through the air.
Examples:
- Radio Waves: Used in Wi-Fi and mobile networks
- Microwaves: Used in satellite communication
- Infrared: Used in TV remotes
Key Features:
- Data travels without wires.
- Suitable for longer distances and outdoor environments.
Difference Between Guided and Unguided Media:
| Feature | Guided Media (Wired) | Unguided Media (Wireless) |
|---|---|---|
| Medium Type | Physical cables | Air or space |
| Data Transfer | Through cables | Through radio or light waves |
| Installation | Complex and costly | Easy and cost-effective |
| Security | More secure | Less secure |
| Distance | Suitable for short to medium distances | Suitable for long distances |
| Examples | Twisted pair, Coaxial, Fiber optic | Wi-Fi, Radio waves, Infrared |
Simple Memory Trick:
- Guided Media: Think “Guided = Guided by Wires.”
- Unguided Media: Think “Unguided = No Wires, Data in the Air.”
What are different Types of Networks?
Computer networks are categorized based on their size and area of coverage. The most common types are LAN, MAN, and WAN.
1. LAN (Local Area Network):
- Definition: A LAN connects computers and devices within a small area, like a home, school, or office.
- Size: Small (within a building)
- Example: Computer lab in a school
- Key Features:
- High-speed connection
- Easy to set up
- Limited to a small area
2. MAN (Metropolitan Area Network):
- Definition: A MAN connects multiple LANs across a city or large campus.
- Size: Medium (within a city)
- Example: Network connecting offices across a city
- Key Features:
- Covers a larger area than LAN
- Used by organizations, universities, and government offices
- Requires more setup and maintenance
3. WAN (Wide Area Network):
- Definition: A WAN connects multiple LANs and MANs across large distances, including countries or continents.
- Size: Very large (global)
- Example: The Internet
- Key Features:
- Covers large distances
- High setup and maintenance cost
- Can use satellites and undersea cables
Comparison Table:
| Feature | LAN | MAN | WAN |
|---|---|---|---|
| Full Form | Local Area Network | Metropolitan Area Network | Wide Area Network |
| Size | Small | Medium | Large |
| Area Coverage | Building or campus | City or large campus | Country or global |
| Speed | Very high | Moderate | Lower than LAN |
| Cost | Low | Medium | High |
| Example | Computer lab | Network in a city | The Internet |
Simple Memory Trick:
- LAN: Think Local = Small area (Home/School)
- MAN: Think Metro = City level (Campus/Offices)
- WAN: Think World = Large distances (Internet)
