Bitcoin is a Filterlink
Imagine you’re trying to replace banks with a global, decentralized financial system. You call it Bitcoin.
Instead of trusting a third party to validate transactions, you decide that Bitcoin will run on a network where each node is responsible for separating false statements (noise) from true statements (signal). You make the nodes compete, so that the winner is the one who has contributed the most resources to the network. By requiring this proof of work, you make spam both expensive and rare. In other words, you’ve separated the signal from the noise.