How does Ethereum work, anyway?

The blockchain is a purely distributed peer-to-peer system of ledgers that utilizes a software unit that consist of an algorithm, which negotiates the informational content of ordered and connected blocks of data together with cryptographic and security technologies in order to achieve and maintain its integrity.

A blockchain is like a place where you store any data semi-publicly in a linear container space (the block). Anyone can verify that you’ve placed that information, because the container has your signature on it, but only you (or a program) can unlock what’s inside the container, because only you hold the private keys to that data, securely.