Filecoin

Filecoin is a decentralized storage network built on IPFS, where users pay to store data with independent storage providers across the network instead of a centralized cloud storage company, with the blockchain used to verify that providers are actually storing the data they're paid for.

Developers integrate with Filecoin through its APIs/SDKs to store and retrieve data in a way that isn't dependent on any single storage provider staying in business, trading the convenience of a centralized provider for censorship-resistance and provider redundancy.

Used in web3/decentralized applications wanting storage that matches the decentralization properties of the rest of their stack, rather than pairing a decentralized app with centralized cloud storage.