Think beyond the Bitcoin as wellknown blockchain application and you will discover plenty of use cases where trust in interlinked transactions is primordial. Also 'transaction' is as broad as exchanging services (incentivised) for other values (represented by tokens). Its about new types of economy.
Yet, blockchain is a technology using cryptographic and distributed computing to name a few, but as powerful as the Internet Protocol in the Internet. But it is a technology that can spawn so many use case.