Best pdf editor software

 Here are some excellent PDF editor software options—both free and paid—depending on what you need (edit text, compress, merge, annotate, sign, etc.):

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✅ Best Free PDF Editor Software

1. PDF-XChange Editor (Windows)

• Powerful editing tools

• OCR support

• Add/remove text, images, annotations

• Free version has minor watermark on some features

Best for: Everyday editing & annotation

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2. LibreOffice Draw (Windows / Mac / Linux)

• Fully free & open-source

• Can edit PDF text and images

• Good for rearranging content

Best for: Free alternative to Adobe Acrobat

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3. PDFsam Basic (Windows / Mac / Linux)

• Split, merge, rotate, extract pages

• Does not edit text

• 100% free & offline

Best for: Page management

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4. Sejda PDF Editor (Web + Desktop)

• Edit text directly

• Insert images, signatures

• Compress, merge, crop

• Daily task limits on free version

Best for: Quick online edits

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5. Smallpdf (Web)

• Compress, convert, merge

• Add annotations

• Limited free usage

Best for: Simple online PDF tasks

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💼 Best Paid PDF Editors (Professional Level)

1. Adobe Acrobat Pro DC

• Industry standard

• Edit ANY PDF (text, images, links, formatting)

• OCR, e-sign, redaction, compression

Best for: Full professional editing

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2. Foxit PDF Editor

• Cheaper than Adobe

• Fast and lightweight

• Advanced editing

• Business-friendly

Best for: Office use

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3. Nitro PDF Pro

• Similar tools to Adobe

• One-time purchase option

• Great for batch processing

Best for: Users avoiding subscription fees

Best cryptocurrency

 

“Best” cryptocurrency depends on your purpose — investing, trading, long-term holding, payments, or building apps.
Here’s a clean, practical list of top cryptocurrencies by category (2025).

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⭐ Overall Strongest / Most Established

1. Bitcoin (BTC)

• King of crypto, lowest risk compared to others
• Best for long-term holding
• Limited supply (21 million)

2. Ethereum (ETH)

• Smart contract leader
• Huge ecosystem (DeFi, NFTs, apps)
• Strong developer support

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🚀 High-Potential Platforms (Smart Contract / Web3 Leaders)

3. Solana (SOL)

• Very fast & cheap transactions
• Strong growth in DeFi + memecoins
• Growing developer activity

4. Polkadot (DOT)

• Interoperability between blockchains
• Strong technology & governance

5. Cardano (ADA)

• Research-based approach
• Scalable & energy efficient

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⚡ Strong Layer-2 Scaling Solutions

6. Polygon (MATIC → POL)

• Popular for low-cost Ethereum transactions
• Used by enterprises (Nike, Starbucks)

7. Arbitrum (ARB)

• Top Ethereum L2 by activity
• Fast & cheap

8. Optimism (OP)

• Supports multiple L2 chains
• Backed by major developers

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💡 AI + Crypto Projects (Fast-growing sector)

9. Render (RNDR)

• Decentralized GPU network for AI/3D rendering
• Massive demand growth

10. Fetch.ai (FET → ASI)

• AI agents + blockchain
• Part of big ASI (Artificial Superintelligence) merger

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🪙 Stablecoins (For Safety / Savings / Trading)

USDT (Tether) – Most widely used

USDC – Most regulated & trusted

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🏆 Which is BEST for you?

✔ Best for Long-term investors:

• BTC, ETH

✔ Best for growth / high potential:

• SOL, RNDR, ASI

✔ Best for beginners:

• BTC, ETH, MATIC(POL)

✔ Lowest risk (stable):

• USDT, USDC

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⚠️ Important Note

Cryptocurrency prices are highly volatile. Never invest money you can't afford to lose.

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Difference between ethical and non ethical hackers in details

 

Here is a clear, detailed, and easy-to-understand difference between Ethical Hackers and Non-Ethical (Malicious) Hackers:

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✅ 1. Meaning

Ethical Hacker (White Hat Hacker)

• A security professional who hacks with permission.
• Their goal is to find vulnerabilities and help organizations fix them.
• They follow laws, rules, and ethical guidelines.

Non-Ethical Hacker

(Black Hat Hacker, Grey Hat Hacker, Cybercriminal)

• Hack systems without permission.
• Main purpose: steal data, damage systems, make money illegally, or cause harm.
• Their actions are illegal and punishable by law.

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✅ 2. Purpose / Intent

Ethical Hacker

• Improve security of systems.
• Protect users and organizations.
• Prevent data breaches.
• Test system strength (penetration testing).

Non-Ethical Hacker

• Steal money or data.
• Sell data on the dark web.
• Attack websites (DDoS, defacement).
• Spread malware, ransomware.
• Spy, blackmail, or sabotage.

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✅ 3. Permission

Ethical Hacker

✔ Always works with written permission from system owner.
✔ Follows a legal contract or NDA.

Non-Ethical Hacker

❌ Hacks without permission.
❌ Violates privacy, security laws, and cybercrime laws.

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✅ 4. Legality

Ethical Hacker

✔ 100% legal.
✔ Follows cyber laws like IT Act 2000 (India) and global frameworks.

Non-Ethical Hacker

❌ Illegal activities.
❌ Punishable with jail, fines, and bans.

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✅ 5. Techniques Used

Both use similar hacking tools, such as:

• Kali Linux
• Metasploit
• Wireshark
• Burp Suite
• Nmap

Difference is in their intention and how they use these tools.

Technique / Tool	Ethical Hacker Uses For	Non-Ethical Hacker Uses For
Port Scanning	Find weaknesses	Break into systems
Social Engineering	Test employee awareness	Steal passwords
Exploits	Demonstrate vulnerabilities	Compromise devices
Malware Analysis	Protect against attacks	Create and spread malware

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✅ 6. Types

Ethical Hackers

• White Hat
• Penetration Tester
• Cybersecurity Analyst
• Bug Bounty Hunter
• Red Team Expert

Non-Ethical Hackers

• Black Hat Hacker
• Grey Hat Hacker
• Script Kiddie
• Hacktivist (political/activist motive)
• Cyber Terrorist
• Ransomware Attacker

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✅ 7. Salary vs Earnings

Ethical Hacker (Legal Job)

• Salary: ₹4 LPA – ₹30 LPA+ (India)
• Bug bounty programs can give lakhs to crores

Non-Ethical Hacker

• No legal salary
• Illegal earnings
• High risk of arrest and lifetime consequences

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✅ 8. Impact on Society

Ethical Hacker

✔ Protects people and businesses
✔ Strengthens national cybersecurity
✔ Reduces data breaches
✔ Keeps online systems safer

Non-Ethical Hacker

❌ Steals money and personal data
❌ Causes financial and emotional damage
❌ Creates fear & mistrust in digital systems
❌ Harms national security

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🧾 9. Summary Table

Feature	Ethical Hacker	Non-Ethical Hacker
Permission	✔ Yes	❌ No
Intent	Security & Protection	Damage & Theft
Legal Status	Legal	Illegal
Tools Used	Same tools but ethically	Same tools for crime
Employer	Companies, Govt, Agencies	No legal employer
Result	Increased security	Data loss & cybercrime

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Limit of cashback on cashkaro while using flipkart

 

It appears CashKaro doesn’t publicize a fixed “maximum cashback limit” per transaction or per day when you use Flipkart — but there are a few relevant points worth knowing:

• On Flipkart purchases via CashKaro you typically get a cashback or “rewards” offer (often shown as “up to 7%” cashback) depending on the sale/offers.
• Once cashback or rewards are confirmed and your total confirmed amount reaches ₹250, you become eligible to withdraw (or redeem) it.
• There is no published cap mentioned by CashKaro that says “you cannot earn more than X rupees cashback” for Flipkart overall — cashback depends on the order amount and offer rate.

✅ What we know about CashKaro + Flipkart cashback

On the CashKaro store page for Flipkart, the cashback (or “Rewards”) rate is shown as “up to 7%” on eligible orders. 

Cashback/Rewards you earn are first marked “Pending,” then become “Confirmed” once the order is validated by the merchant. 

You can withdraw (or redeem) your confirmed balance — either to your bank account via NEFT, or as gift cards (e.g. Flipkart or Amazon) — once your confirmed amount reaches at least ₹ 250. 

Cashback/Rewards entries expire if you don’t log in to your CashKaro account for 2 years. 

⚠️ What is not specified (i.e. no cap)

CashKaro’s public documentation and FAQs do not mention a “maximum total cashback” limit (like per month / per year / lifetime) that a user can earn through Flipkart or any other store.

There is no mention of a cap on number of times you can use Cashback-enabled links.

There is no explicit upper limit on amount per transaction (other than the usual: cashback is calculated on “order value after deducting Supercoins and other charges,” and certain categories might be excluded). 

🔎 Conclusion

As per available public information (2025): there is no defined cap on how much cashback/rewards you can earn overall via CashKaro when shopping on Flipkart. Your earnings are limited only by your purchases (what you buy, how often, order value) and whether cashback offer applies to that order.

If you like — I can also try to dig up user reports or community-thread data (Reddit, forums etc.) to see if people have experienced any effective limits (for example: declined cashback after many orders).

Presentation on Nanotubes

 

Slide 1: Title Slide

Nanotubes: The Building Blocks of Tomorrow

An Introduction to the Tiniest, Strongest Tubes in the World

[Image: A dynamic, high-tech 3D rendering of glowing, interconnected carbon nanotubes against a dark, futuristic background.]

Slide 2: What are Nanotubes?

Imagine a sheet of paper, just one atom thick, rolled into a perfect, seamless tube.

• Carbon Nanotubes (CNTs) are cylindrical molecules made of carbon atoms.

• They are a form (allotrope) of carbon, just like diamond and graphite.

• Their diameter is measured in nanometers – up to 100,000 times smaller than a human hair!

[Image: A clear diagram showing a flat, honeycomb sheet of graphene on the left, which then rolls up to form a cylindrical carbon nanotube on the right.]

Slide 3: The Main Types

There are two main families of carbon nanotubes:

1. Single-Walled Nanotubes (SWCNTs):

   • Made from a single, one-atom-thick layer of graphene.

   • Extremely thin, with diameters as small as 1 nanometer.

2. Multi-Walled Nanotubes (MWCNTs):

   • Consist of multiple layers of graphene rolled into concentric tubes, like a Russian nesting doll.

   • They are thicker and more complex than SWCNTs.

[Image: A side-by-side comparison. On the left, a simple, single-layer tube representing an SWCNT. On the right, a cross-section showing multiple nested tubes representing an MWCNT.]

Slide 4: Astonishing Properties

Nanotubes are not just tiny; they are mighty.

• Incredible Strength: Pound for pound, nanotubes are the strongest material ever discovered – over 100 times stronger than steel.

• Excellent Conductors: They can conduct electricity better than copper and heat better than diamond.

• Extremely Lightweight: Their strength-to-weight ratio is unparalleled.

• Large Surface Area: A small amount of nanotubes has a massive surface area, useful for chemical reactions.

[Image: An infographic with four icons. 1) A nanotube easily holding up a huge weight. 2) A lightning bolt flowing through a nanotube. 3) A feather next to a nanotube to show it's lightweight. 4) An unfolded tube showing a large surface.]

Slide 5: Applications: Stronger Materials

Making everyday objects lighter and more durable.

• Nanotubes are mixed with traditional materials (like polymers, metals, and concrete) to create super-strong, lightweight composites.

• Uses:

  • Aerospace parts for planes and satellites.

  • Stronger, lighter sporting goods (bicycle frames, tennis rackets, golf clubs).

  • Wind turbine blades that are longer and more efficient.

[Image: A picture of a modern carbon fiber bicycle. A magnified "zoom-in" circle shows a microscopic view of the material, with nanotubes embedded within the fibers.]

Slide 6: Applications: Next-Gen Electronics

Powering smaller, faster, and more efficient devices.

• Their excellent conductivity and small size make them ideal for revolutionizing electronics.

• Potential Uses:

  • Replacing silicon to create faster, smaller computer chips.

  • Transparent, conductive films for flexible touchscreens and displays.

  • Ultra-sensitive sensors for detecting chemicals or pollutants.

[Image: A person holding a futuristic, completely transparent and flexible smartphone that is displaying vibrant graphics.]

Slide 7: Applications: Health & Medicine

A new frontier in diagnosing and treating disease.

• The hollow structure of nanotubes allows them to carry medicine directly to targeted cells.

• Potential Uses:

  • Targeted Drug Delivery: Loading nanotubes with chemotherapy drugs to attack cancer cells without harming healthy ones.

  • Bio-imaging: Attaching to specific cells to make them visible for medical scans.

  • Biosensors: Creating tiny devices that can detect disease markers in the body.

[Image: A medical animation showing nanotubes (represented as small cylinders) carrying drug molecules and attaching themselves to a single diseased cell.]

Slide 8: Challenges and the Future

What's next for nanotubes?

• Challenges:

  • High cost of production.

  • Ensuring high purity and sorting different types of nanotubes.

  • Understanding long-term environmental and health impacts.

• The Future: As research solves these challenges, nanotubes could be key to innovations in energy storage (better batteries), water filtration, and much more.

[Image: A split photo. One side shows scientists in a modern lab working with complex equipment. The other side shows a graphic of a clean city of the future powered by nanotube-based technologies.]

Slide 9: Conclusion

• Carbon nanotubes are a revolutionary material with extraordinary strength, conductivity, and potential.

• They are already beginning to improve materials, electronics, and medicine.

• They represent a giant leap in nanotechnology, paving the way for a future of smarter, stronger, and more efficient technology.

Slide 10: Q&A

Thank You

Questions?

Presentation on Letter Writing

 

Slide 1: Title Slide

The Art of Letter Writing

A Guide to Effective and Purposeful Communication

Slide 2: Introduction

What is a Letter?

• A letter is a written message conveyed from one person to another, typically through the post or another delivery service.

• Despite the rise of digital communication, letter writing remains a crucial skill for formal, personal, and professional correspondence.

Why is it still important?

• Provides a formal record of communication.

• Conveys a sense of importance and personal touch.

• Required for many official purposes (job applications, legal notices, etc.).

• Helps develop writing and communication skills.

Slide 3: Main Types of Letters

1. Formal Letters:

• Written for official or professional purposes.

• Follow a strict format and use formal language.

• Examples: Business letters, job applications, letters to government officials, letters to the editor.

2. Informal Letters:

• Written to friends, family, or acquaintances.

• Use a personal, casual tone and have a flexible format.

• Examples: Letters to parents, friends, or relatives, thank-you notes, invitations.

Slide 4: Deep Dive: Formal Letters

Purpose: To inform, request, complain, inquire, or apply in a professional setting.

Key Characteristics:

• Structure: Follows a specific, prescribed format.

• Tone: Professional, objective, and polite.

• Language: Uses formal vocabulary and avoids slang, contractions, or colloquialisms.

• Content: Precise, relevant, and to the point.

Slide 5: Structure of a Formal Letter

1. Sender's Address: Your address (top left).

2. Date: The date the letter is written (below sender's address).

3. Receiver's Address: The address of the person you are writing to (below the date).

4. Subject: A brief line summarizing the letter's purpose.

5. Salutation: The formal greeting (e.g., "Dear Sir/Madam," or "Dear Mr. Smith,").

6. Body of the Letter: The main message, typically 2-3 paragraphs.

7. Complimentary Close: The formal closing (e.g., "Yours faithfully," "Yours sincerely,").

8. Signature: Your handwritten signature, followed by your typed full name.

Slide 6: Writing the Body of a Formal Letter

• Paragraph 1: Introduction

  • State the purpose of the letter directly. Why are you writing?

  • Example: "I am writing to apply for the position of Marketing Manager advertised on..."

• Paragraph 2: Main Content

  • Provide all the necessary details, information, or arguments. Be clear and logical.

  • This is the core of your letter.

• Paragraph 3: Conclusion

  • Summarize your purpose and state what you expect. This could be a call to action or a concluding statement.

  • Example: "I look forward to hearing from you at your earliest convenience."

Slide 7: Deep Dive: Informal Letters

Purpose: To connect with people you know personally, share news, or express feelings.

Key Characteristics:

• Structure: Flexible and less rigid than a formal letter.

• Tone: Personal, warm, and conversational.

• Language: Casual language, contractions, and colloquialisms are acceptable.

• Content: Can be about any personal topic.

Slide 8: Structure of an Informal Letter

1. Sender's Address: Your address (top left or right).

2. Date: The date of writing.

3. Salutation: A warm, personal greeting (e.g., "Dear Mom," "Hi [Friend's Name],").

4. Body of the Letter: The main message, written in a conversational style. You can use paragraphs as you see fit.

5. Complimentary Close: A friendly closing (e.g., "With love," "Best wishes," "Your friend,").

6. Signature: Your first name.

Slide 9: Principles of Good Letter Writing

• Purpose: Always be clear about why you are writing the letter.

• Audience: Write with the recipient in mind. Use an appropriate tone and language.

• Clarity: Use simple, direct language. Avoid ambiguity.

• Conciseness: Be brief and to the point, especially in formal letters.

• Accuracy: Ensure all information (names, dates, addresses) and grammar are correct.

Slide 10: Common Mistakes to Avoid

• Incorrect Format: Not following the standard format for formal letters.

• Spelling and Grammar Errors: Creates a poor impression. Always proofread.

• Wrong Tone: Being too casual in a formal letter or too stiff in an informal one.

• Vague Subject Line: The recipient won't know the letter's purpose at a glance.

• Forgetting to Sign: An unsigned letter is incomplete and invalid in formal contexts.

Slide 11: Conclusion

• Letter writing is a timeless and essential skill.

• Understanding the difference between formal and informal letters is key.

• Following the correct structure and principles of good writing ensures your message is received clearly and effectively.

• Practice is the best way to become a confident letter writer.

Slide 12: Q&A

Thank You

Questions?

Presentation on Noting and Drafting

 

Slide 1: Title Slide

Noting & Drafting: The Backbone of Official Communication

A comprehensive guide to effective decision-making and communication.

Slide 2: Introduction

What are Noting and Drafting?

• Noting: The process of writing remarks on a file or document to analyze a problem and suggest a course of action. It is the "thinking" part of the process, done internally to facilitate decision-making.

• Drafting: The process of preparing a formal, written communication (like a letter, memo, or order) that will be sent out. It is the "acting" part of the process, based on the decisions made.

Why are they important?

• Ensure clarity and consistency in decision-making.

• Create a permanent record of the thought process.

• Form the basis for all official correspondence.

• Improve administrative efficiency and accountability.

Slide 3: All About Noting

Purpose of a Note:

• To examine a case or issue.

• To connect it with relevant rules, precedents, and policies.

• To suggest a clear course of action or a decision for a higher authority.

Characteristics of a Good Note:

• Concise: Brief and to the point.

• Clear: Unambiguous and easy to understand.

• Objective: Based on facts, rules, and logic, not personal feelings.

• Self-Contained: Provides all necessary information for a decision.

Slide 4: How to Write an Effective Note

1. Reference: Always start by referring to the correspondence or issue you are noting on. Use the file/reference number.

2. Identify the Problem: Clearly state the core issue that needs a decision.

3. Analyze: Examine the issue in light of:

   • Existing rules and regulations.

   • Previous decisions (precedents).

   • Relevant data and facts.

4. Discuss Options: Briefly discuss the possible solutions or courses of action.

5. Recommend: Clearly state your proposed solution or recommendation. Your suggestion should be a direct consequence of your analysis.

6. Sign Off: End with your signature, name, and designation.

Slide 5: All About Drafting

Purpose of a Draft:

• To formally communicate a decision, request, or piece of information.

• To create a legally and officially sound document.

The 5 C's of Drafting:

• Clarity: The meaning should be plain and simple. Avoid jargon.

• Correctness: Information, grammar, and spelling must be accurate.

• Conciseness: Use the fewest words necessary to convey the message.

• Completeness: The draft must contain all necessary information for the recipient.

• Courtesy: The tone should be appropriate and respectful.

Slide 6: The Drafting Process

1. Understand the Decision: Be clear on the decision taken in the "noting" stage that you need to communicate.

2. Identify the Audience: Who are you writing to? Tailor the language and tone accordingly.

3. Outline the Structure: Plan the sequence of your points (e.g., introduction, main body, conclusion/action).

4. Write the First Draft: Focus on getting the content down logically. Don't worry about perfection.

5. Revise and Edit: Improve clarity, conciseness, and flow. Check for factual accuracy.

6. Proofread: Read through one last time to catch any spelling, grammar, or punctuation errors.

Slide 7: Noting vs. Drafting - Key Differences

Feature	Noting	Drafting
Purpose	Internal decision-making	External communication
Audience	Colleagues, Superiors (Internal)	Other departments, Public (External)
Style	Informal, brief, analytical	Formal, structured, polite
Format	Written on file, can be handwritten	Typed, follows specific formats
Content	Analysis, opinions, recommendations	Decisions, information, requests
Outcome	A decision is made.	An official document is sent.

Slide 8: Common Mistakes to Avoid

• Vagueness: Using unclear language in notes or drafts.

• Incompleteness: Leaving out critical facts or context.

• Beating Around the Bush: Not getting to the point quickly.

• Factual Errors: Providing incorrect data or rule citations.

• Improper Tone: Using overly casual or aggressive language in a draft.

• Mixing Noting and Drafting: Writing a long, rambling note when a clear draft is required.

Slide 9: Conclusion

• Noting is the intellectual process of applying your mind to an issue.

• Drafting is the skill of communicating the outcome of that process.

• Mastering both skills is fundamental for administrative effectiveness. They ensure that decisions are well-reasoned and communications are clear, professional, and actionable.

Slide 10: Q&A

Thank You

Questions?