Centralization and decentralization in blockchain and crypto are a theme with a lot of debates over it. So Amazon Web Services decided to work on both sides in its blockchain endeavours.
Some people do not consider decentralization as a vital thing and some people do. AWS found out that some customers are okay with centralized trust if they will have an opportunity of immutable verifiable record of every change that was made. Taking this into consideration AWS built the Amazon Quantum Ledger Database. Rahul Pathak GM of AWS blockchain told that the concept is to have a cryptographically verifiable, tamper-proof ledger that you can doubt and cooperate with, but it is controlled by a single entity. This kind of solution will work effectively in cases when a customer will like to audit trails, but won’t care about distributed trust.
Also, AWS created the Amazon Managed Blockchain for those, who are looking for a more decentralized solution. Pathak explained that this one was specially created for those who wanted the “ledger” without one regulating institution. These consumers wanted a decentralized trust system.
Though these systems were announced on November 2018, Pathak noted that QLDB is still in preview and the AMB went into general availability only at the end of this April.