Actually, blockchain is a very high-tech technology in the field of network, internet or data security which provides a high end encryption as well as users privacy.
This, blockchain technology can be implemented in various fields like in cloud storage of user's data, social media (for privacy of user interactions), banking technology & even many more.
In present time, its just a start or very beginning phase of blockchain where lots of applications usage can't be predicted by normal people but very soon in near future every existing technology can be replaced by blockchain technology and will bring 100% usage of crytocurrencies too.