Blockchain is simply a new type of database. Rather than traditional databases (SQL or NoSQL) that are controlled by single entities, blockchain can be shared by a group of non-trusting parties without requiring a central administrator.
Michael and I get asked the same question all the time:
“Can I use a blockchain for this?”
We typically respond with:
“Can you do that with a regular database?”
And, in more cases than not, the answer is “Yes”.
This is because if trust and robustness aren’t an issue, there’s nothing a blockchain can do that a regular database cannot. Remember, blockchains are useful for sharing data with a group of non-trusting parties.
“The blockchain has the ability to enhance reliability in business processes by eliminating political and economic risks associated with trusting a centralized system.” — Vitalik Buterin