Blockchain is an entirely different concept - it's an Internet-based, open-source, [usually encrypted] flat DATABASE (called "ledger") which is distributed / replicated among many computers on the Internet for the purpose of keeping records, such as financial or other transactions between parties on the same blockchain network.
Because it's "flat" and relatively inefficient to access (traverse the records to verify the parties and data to "clear" the transaction) it grows very fast in size and generally provides no benefit relative to regular databases currently in use for such purposes, like various versions of SQL or newer like MongoDB or MariaDB and non-structured DB systems like Hadoop.
For financial purposes transactions over blockchain could be costly compared to regular debit transactions (with no credit risk) and much slower compared to such as Visa and Mastercard, but it might have limited uses when database is going to have a finite runtime and size, though it still difficult to imagine that it would give any advantage over regular database with transactions that could be encrypted for security if needed. In other words, blockchains have an inherent scalability and processing speed problem which is getting worse as the database / ledger gets bigger with use.
A few articles explaining advantages and many disadvantages of blockchain, mainly by discussing case use of Bitcoin which is built on it (though not limited to Bitcoin, as some new blockchain systems are trying to improve on certain aspects of Bitcoin blockchain, such as security and speed) :
Ten years in, nobody has come up with a use for blockchain - CNBC, by Kai Stinchcombe, 2017 December 26
What Is Bitcoin Good For? - BL, by Megan McCardle, 2017 December 22
Bitcoin Is an Implausible Currency - BL, by Megan McCardle, 2017 December 27
There are a lot of excitement around blockchain, especially in financial industry, mostly due to encryption and potentially faster debit "clearance" mechanism, and a lot of experimental small-scale trials among several banks, delivering "proof-of-concept" (i.e., it can work) but it's a long way, if ever, from actually deploying it on a wide-scale commercial trusted system which is generally pretty well served by existing systems, even including anonymity of transactions.
Thank you for the education.
Thanks for your very helpful reply.
I’ll read your links tomorrow when I have more time.