What is difference between CopyRight and CopyLeft

 📜 Copyright

• What it is:

• A legal right automatically given to the creator of an original work (book, music, software, etc.).

• It gives the creator exclusive rights to use, distribute, modify, and license the work.

• How it works in software:

• When you write code, you own the copyright by default.

• You can then decide:

• Keep it private,

• Sell licenses,

• Or open-source it under a license (MIT, GPL, etc.).

👉 Copyright = ownership + control.

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🔄 Copyleft

• What it is:

• A licensing strategy that uses copyright law in reverse: instead of restricting sharing, it enforces sharing.

• Introduced by Richard Stallman (FSF, GNU project).

• How it works:

• Copyleft licenses (like GPL, AGPL) say:

“You can use, modify, and distribute this software freely — but if you distribute or offer it as a service, you must also share your modifications under the same license.”

• Effect:

• Ensures the software and all its derivatives remain open-source.

• Prevents companies from taking open-source software, improving it, and releasing it as closed-source.

👉 Copyleft = open-source with mandatory sharing.

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⚖️ Example Contrast

Case Copyright Copyleft

You write software You automatically own the copyright You can choose to apply a copyleft license

If others use it They need your permission (license) They can use it, but must share improvements

Closed-source use Allowed (if you sell/proprietary license) Not allowed — derivatives must stay open-source

Example licenses Proprietary EULAs, MIT, Apache GPL, AGPL, LGPL

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🔑 Simple Analogy

• Copyright is like “No one may copy or use my book without my permission.”

• Copyleft is like “You may copy and modify my book, but if you publish it, you must also let others copy and modify your version.”

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✅ So:

• Copyright = protection & exclusivity.

• Copyleft = freedom, but with the condition that freedom must continue downstream.

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👉 Would you like me to also make a diagram/visual flow showing how software changes hands differently under Copyright-only, Permissive licenses (MIT/Apache), and Copyleft (GPL/AGPL)?