Transaction
A discrete unit of work, involving one or more configuration items, which changes the state of a system.
Impact
ACID transactions (Atomicity, Consistency, Isolation, Durability) are the gold standard for data integrity.
Weinto take
In distributed systems, we often trade ACID for BASE (Basically Available, Soft State, Eventual Consistency). We accept that the data might be stale for a few milliseconds in exchange for the system never going down.