What is ACID?

Four “rules” ensure that a database transaction is timely. When a database adheres to these rules, it is said to be ACID-compliant.

• A for Atomicity: all database transactions can be broken down in smaller parts. Atomicity refers to the integrity of the whole transaction, not just one specific part. When there is something wrong with one part and fails, all the other parts will also fail.
• C for Consistency: Only data that complies with a specific set of rules can be written to the database. If a transaction occurs that does not comply, the database will roll back to a state that does.
• I for Isolation: The ability of a database to process multiple transactions in a way that they do not affect one another.
• D for Durability: This rule ensures that the data is effectively saved when a transaction is completed, even when a system failure occurs.