The word mining originates in the context of the gold analogy for crypto currencies. Gold or precious metals are scarce, so are digital bitcoin mining ubuntu vs windows security, and the only way to increase the total volume is through mining. Ethereum, like all blockchain technologies, uses an incentive-driven model of security. Consensus is based on choosing the block with the highest total difficulty.
Miners produce blocks which the others check for validity. The Ethereum blockchain is in many ways similar to the Bitcoin blockchain, although it does have some differences. As dictated by the protocol, the difficulty dynamically adjusts in such a way that on average one block is produced by the entire network every 15 seconds. We say that the network produces a blockchain with a 15 second block time.