Atomicity :- A transaction is a unit or work in which a series of operations occur between the BEGIN TRANSACTION and END TRANSACTION statments of an application. A transaction executes exactly once and is atomic - all the work is done or none of it is.

Consistency :- A transaction is a unit of integrity because it preserves the consistency of data, transforming one consistent state of data into another consistent state of data.

Isolation :- A transaction is a unit of isolation allowing concurrent transactions to executes and isolate one transaction from other transaction.

Durability :- A transaction is a unit of recovery. If a transaction succeeds, the system gurantees that it updates will persit, even if the computer crashes immediately after the commit.


Transaction must be Atomic (it is one unit of work and does not dependent on previous and following transactions), Consistent (data is either committed or roll back, no “in-between” case where something has been updated and something hasnot), Isolated (no transaction sees the intermediate results of the current transaction), Durable (the values persist if the data had been committed even if the system crashes right after)