Mina is the first cryptocurrency protocol with a succinct blockchain. Current cryptocurrencies like Bitcoin and Ethereum store hundreds of gigabytes of data, and as time goes on, their blockchains will only increase in size. With Mina however, no matter how much the usage grows, the blockchain always stays the same size - about 22kb (the size of a few tweets). This means participants can quickly sync and verify the network.
This breakthrough is made possible due to zk-SNARKs - a type of succinct cryptographic proof. Each time a Mina node produces a new block, it also generates a SNARK proof verifying that the block was valid. All nodes can then store the small proof, as opposed to the entire chain. By not having to worry about block size, the Mina protocol enables a blockchain that is decentralized at scale.