The inherent property of a blockchain to store data makes it, more or less, a database. But the ways in which it differs from, and is indeed, better than a conventional database are numerous.
In a conventional database, a centralized client-server network is administered by a designated authority. Blockchain, on the other hand, is decentralized or open-source, which means authority is distributed over the network. In other words, the blockchain being a trustless network in its entirety, provides for a more credible environment to park data.
Conventional databases offer little to no transparency as they belong to a centralized organization, which has been quite usual since the inception of conventional databases. However, one of the reasons why blockchain technology is considered the most groundbreaking technological revolution since the ‘World Wide Web’ itself is that it allows anyone to cross-verify a piece of data with the help of a ‘Transaction Hash ID’.
In terms of permanency of data stored, blockchain technology shines exactly where a conventional database fails to impress. While a conventional database allows a single designated authority or node to create, erase, or modify data, blockchain being a distributed network allows a node to only add or view data. Any modification or removal of data by a node would require consensus from the majority of nodes, also called 51% attack, which is hypothetical so far, as gaining control over such a high number of nodes is pretty much impossible.