ACID acronym standing for these four concepts: atomicity, consistency, isolation and durability.
The context here is when we're modifying records in, let's say a database. And we can be modifying lots of different records across different tables, anything we want. And the point is they're all lumped into one transaction. The context for each one of these concepts. So, atomicity means that the entire transaction either needs to succeed or needs to fail. Consistency is the sort of any data written into the database must be valid according to all defined rules .Now the question is wherethese defined rules come from? Sometimes they're actually integrity constraints in the database, sort of business logic rules, enforced by the application . So, it's a little bit difficult to proving a system which is achieved application level consistency but that's the goal should be. Isolation means that while the transaction is occurring, other readers and writers can't sniff partially completed values. you can't sniff values of data items before the transaction is complete. And then durability just means that if you report back that the transaction succeeded, it needs to have actually succeeded. Meaning that it needs to be written out to some kind of non-volatile storage, so that if the power goes out and the machine crashes, you don't say transaction that I accepted yesterday or committed yesterday and you need to do that again because it didn't take