Polkadot is a public blockchain launched by the original core developers of Ethereum. It aims to solve the two major problems that prevent the spread and acceptance of blockchain technology today: instant scalability and extensibility. Polkadot plans to integrate the private chain / alliance chain into the consensus network of the public chain, while maintaining the original data privacy and permission characteristics of the private / alliance chain. It can connect multiple blockchains to each other.
Polkadot is a scalable heterogeneous multi-chain system. This means that unlike previous single blockchain implementations that focus on different levels of potential application functions, Polkadot itself is designed to not provide any inherent functional applications. Polkadot provides a relay-chain, on which there can be a large number of verifiable and globally dependent dynamic data structures. We call these parallel structured blockchains paraparas, although it is not required that they must be a chain.
The problem of cross-chain transactions is solved by a simple queue mechanism. This queue uses a Merkle tree to ensure the authenticity of the data. The task of the relay chain is to transfer transactions from the exit queue of the source parachain to the incoming queue of the destination parachain. The forwarded transaction will be referenced on the relay chain, not the transaction of the relay chain itself. In order to prevent one parachain from sending junk transactions to another parachain, it is stipulated that after sending each transaction after the previous block ends, the target parachain's queue cannot be too large. If the queue is too large after the block is processed, the destination parachain will be considered saturated, and the next few blocks will not route transactions to it until the queue drops below the critical value.
Polkadot uses a philosophy of phishing and collecting people by customizing a relatively strict system to avoid malicious operations as much as possible. In essence, polkadot still wants to use systems to solve technical problems.