introduction of pushdown automata

📝 1. What is Facebook & How to Use It

 📝 1. What is Facebook & How to Use It

Introduction

Facebook is one of the most popular social media platforms.

How to Use

Create account

Add friends

Post photos & videos

Features

News Feed

Groups

Marketplace

📝 What is YouTube & How to Use It

 📝 What is YouTube & How to Use It

🎥 Introduction

YouTube is used to watch and upload videos.

📥 Install YouTube

Available by default in most phones

Or install from Play Store

🔍 Search Videos

Open YouTube

Type topic

Click video

👍 Like, Share, Subscribe

👍 Like video

🔔 Subscribe channel

📤 Share with others

📤 Upload Video

Click + button

Select video

Add title & description

Upload

💡 Tips

Use good thumbnails

Upload regularly

Add keywords

🌐What is Google Chrome & How to Use It

 What is Google Chrome & How to Use It

🌐 Introduction

Google Chrome is a fast web browser used to access websites.

📥 Install Chrome

Go to Google

Search “Download Chrome”

Install

🔍 How to Use

Search Anything

Type in search bar → press Enter

Open Website

Example: youtube.com

🧩 Extensions

You can add tools like:

Ad blocker

Grammarly

⚙️ Settings

Change theme

Clear history

Manage passwords

🌐What is Instagram & How to Use It (Full Guide)

 What is Instagram & How to Use It (Full Guide)

📱 Introduction

Instagram is a popular social media app used to share:

Photos 📷

Videos 🎥

Reels 🔥

Stories ⏳

📥 How to Install Instagram

Open Play Store / App Store

Search “Instagram”

Click Install

🔐 Create Account

Open app

Enter mobile/email

Set password

Choose username

📸 Features of Instagram

1. Posts

Upload photos/videos to your profile

2. Reels

Short viral videos

3. Stories

Disappear after 24 hours

4. DM (Direct Message)

Chat with friends

💡 Tips to Grow

Post regularly

Use hashtags

Engage with audience

  

🌐 What is a Chrome Extension?

A Chrome Extension is a small software program that adds extra features to your browser.

👉 Think like:

• Ad blocker → blocks ads

• Grammarly → checks grammar

• Dark mode → changes website theme

So basically, it enhances Chrome functionality without installing full software.

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🧠 How Chrome Extensions Work (Basic Logic)

• Built using HTML, CSS, JavaScript

• Run inside Chrome browser

• Can interact with:

  • Web pages

  • Browser tabs

  • User actions (click, typing)

👉 Example:
When you install an ad blocker → it scans webpage → removes ads automatically

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📥 Method 1: Install from Chrome Web Store (Step-by-Step)

This is the easiest and safest method.

🔹 Step 1: Open Chrome

Open your browser (Google Chrome)

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🔹 Step 2: Open Chrome Web Store

Search on Google:
👉 Chrome Web Store
or open: https://chrome.google.com/webstore

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🔹 Step 3: Search Extension

• Use search bar (top-left)

• Example:

  • “AdBlock”

  • “Grammarly”

  • “Video Downloader”

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🔹 Step 4: Select Extension

• Click on extension name

• You will see:

  • Description

  • Reviews

  • Permissions

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🔹 Step 5: Add to Chrome

• Click “Add to Chrome”

• A popup will appear

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🔹 Step 6: Confirm Installation

• Click “Add Extension”

👉 Chrome will download and install it automatically

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🔹 Step 7: Extension Installed ✅

• You will see icon in top-right corner

• Or click 🧩 (Extensions icon)

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📌 How to Use Installed Extension

1. Click Extensions icon (🧩)

2. Find your extension

3. Click Pin 📌 to show it on toolbar

4. Click extension icon to use it

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⚙️ Method 2: Manual Installation (Advanced)

Used when:

• You download extension from GitHub

• You create your own extension

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🔹 Step 1:

Open Chrome and go to:

chrome://extensions/

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🔹 Step 2:

Turn ON Developer Mode (top-right)

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🔹 Step 3:

Click “Load unpacked”

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🔹 Step 4:

Select extension folder from your computer

👉 Now extension will be installed

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📦 Types of Extension Files

Type	Meaning
.crx	Chrome extension file
Folder	Unpacked extension (for developers)

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⚠️ Important Safety Rules

👉 Always remember:

• Install from Chrome Web Store only

• Check:

  • ⭐ Ratings

  • Reviews

  • Number of users

• Avoid unknown extensions

• Don’t give unnecessary permissions

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🚀 Real-Life Example

👉 Suppose you install AdBlock

• You open YouTube

• Ads try to load

• Extension blocks them instantly

👉 Result: Smooth experience

  

📱 What is WhatsApp?

WhatsApp is a free messaging app used to:

• Send messages 💬

• Make calls 📞

• Share photos/videos 📷

• Send documents 📄

👉 It works using internet (data/WiFi) instead of SMS.

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🧠 Basic Working

• You create an account using your mobile number

• WhatsApp connects you with contacts saved in your phone

• Messages are sent instantly via internet

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📥 Step 1: Install WhatsApp

On Mobile (Android / iPhone)

1. Open Play Store (Android) or App Store (iPhone)

2. Search: WhatsApp

3. Click Install

4. Wait for download

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🔐 Step 2: Create Account

First-time setup

1. Open WhatsApp

2. Enter your mobile number

3. You will receive an OTP (verification code)

4. Enter OTP

5. Add:

   • Name

   • Profile photo (optional)

👉 Done! Your account is ready ✅

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💬 Step 3: Send Message

How to chat

4

1. Open WhatsApp

2. Tap on a contact

3. Type message

4. Press Send (➤)

👉 Message will be delivered instantly

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📞 Step 4: Make Calls

Voice & Video calls

4

• Open chat of person

• Tap:

  • 📞 = Voice call

  • 📹 = Video call

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📎 Step 5: Send Photos, Videos, Files

Sharing media

4

1. Open chat

2. Tap 📎 (attachment icon)

3. Choose:

   • Photo / Video

   • Document

   • Location

4. Send

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👥 Step 6: Create Group

Group chat

4

1. Tap 3 dots (⋮)

2. Click New Group

3. Select members

4. Add group name

👉 Now you can chat with multiple people

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🌐 WhatsApp Web (Use on Laptop)

👉 You can also use WhatsApp on PC

1. Open browser

2. Go to: WhatsApp Web

3. Open WhatsApp on phone

4. Tap Linked Devices → Link a Device

5. Scan QR code

👉 Now WhatsApp will open on your computer