What is IPFS (InterPlanetary File System), and how does it integrate with Ethereum?

Okay, no worries. Let's chat about this in plain language.

What is IPFS? A Down-to-Earth Explanation

You can imagine IPFS (InterPlanetary File System) as a globally shared, never-down "super cloud storage drive." But it has a fundamental difference from the cloud storage services we usually use, like Baidu Netdisk or Dropbox.

Imagine how we find things on the internet today (HTTP)

When we browse the internet now, we rely on "addresses." For example, if you want to see a picture of a cat, your browser will visit a URL like http://someserver.com/images/cute_cat.jpg.

This is like going to a library to borrow a book; you must know which library, which floor, which shelf, and which exact spot 📍 the book is located.

• Here's the problem: If that server (library) closes down, gets attacked, or the administrator deletes the picture, you'll never be able to see it again, even if countless other people around the world have an identical copy stored on their computers.

Now, let's look at how IPFS finds things (Content Addressing)

IPFS doesn't ask "where is the file?", but rather "what does the file look like?"

When you store a cat picture into IPFS, IPFS calculates a unique "fingerprint" (more technically called a "hash value") based on the content of the picture itself, like a long string of characters such as QmX....

When you want to see that picture, you directly broadcast to the IPFS network: "Who has the file with the fingerprint QmX...?"

All computers (nodes) in the network that have that picture will respond, and then transfer the picture to you from the closest or fastest node.

This is like going to a library to borrow a book; you no longer care where the book is. You simply shout: "I want to borrow the book The Three-Body Problem (ISBN: xxx)!" 📚 As long as any connected library worldwide has that book, you can borrow it.

Key Features of IPFS

• Decentralized: Files are not stored on a single company's server, but are distributed across tens of thousands of volunteer computers worldwide. No central point means no single point of failure.
• Content-Addressed: The same file, no matter how many times it's stored, will always have the same "fingerprint" (address). Any slight modification to the content will result in a completely different fingerprint. This ensures the authenticity and immutability of the file.
• More Resilient: As long as at least one person in the network still stores a file, it will never be lost. The more people who download it, the more copies exist, and the download speed can potentially increase.

So, how do IPFS and Ethereum 'work together'? 🤝

Once you understand IPFS, this part becomes much easier to grasp.

First, you need to know that the Ethereum blockchain has a "flaw": storing data on it is both expensive and slow.

The Ethereum blockchain is like a "super secure but incredibly expensive miniature safe." You can efficiently record things like who owns what (e.g., an NFT) or who transferred money to whom—these short pieces of text information are perfect. But if you try to directly cram in a high-definition image, a video, or a contract document, the cost would be astronomical, and it would slow down the entire network.

This is where IPFS comes to the rescue. IPFS is like a "massive, affordable, and distributed warehouse."

The Golden Combo: Ethereum + IPFS

Their cooperation model is very simple and efficient:

1. Upload large files (such as an image, a video, or website frontend files) to the IPFS network.
2. IPFS will return a unique "fingerprint" (hash value) to you, for example, ipfs://QmX.... This fingerprint is short—just a string of characters.
3. You record this short "fingerprint" in an Ethereum smart contract. For instance, in your NFT contract, you record: "The image corresponding to this NFT has the IPFS fingerprint ipfs://QmX...." Storing this small piece of text on the blockchain is extremely cheap.
4. When someone needs to view the file, they first access Ethereum, read the IPFS "fingerprint" from the smart contract, and then retrieve the corresponding file from the IPFS network to display it.

A prime example is NFTs 🖼️.

When you buy an NFT, what you truly own on Ethereum is the "proof of ownership" (a Token) for that NFT. This proof contains the IPFS address pointing to the artwork's image. The artwork image itself, being a large file, is securely stored within the IPFS network.

This achieves a perfect synergy:

• Ethereum: Handles the core, most expensive "ownership confirmation" and "logic" aspects. It tells you "who owns this" and "where it points." It acts like an immutable "property deed."
• IPFS: Is responsible for storing large volumes of data that need to be preserved permanently and decentrally. It acts like the "house" itself.

In Summary

Ethereum is like the "ledger" or "certificate" that records ownership, while IPFS is the decentralized warehouse that stores the "digital asset" described on that certificate.

Their combination allows decentralized applications (DApps) to leverage the security, transparency, and immutability of the blockchain, while also economically handling large data like images and videos. It's a classic partnership in the current Web3 world.