Transaction is a sequence of operation performed as a single
logical unit of work which, all the steps must be performed or none. ACID stands for Atomicity, Consistency, Isolation, Durability. These are the properties of a transaction
Transaction has five main properties called ACIDS:
All parts of the transaction are executed or else the transaction is aborted.
Indicates the permanence of the database's consistent state. When a transaction is
completed the database reaches a consistence state.
Means that the data used during the execution of a transaction cannot be used by the a second transaction until the first transaction is complete.
Ensures that once transaction changes are committed, they cannot be lost even in the event of system failure.
Ensures that concurrent execution of several transaction yields consistent results. This
property is important in a multi-user and distributed databases, where multiple transaction are likely to be executed concurrently