ACID Properties :-

In computer science, ACID (Atomicity, Consistency, Isolation, Durability) is a set of properties of database transactions. In the context of databases, a single logical operation on the data is called a transaction. For example, a transfer of funds from one bank account to another, even involving multiple changes such as debiting one account and crediting another, is a single transaction.

Jim Gray defined these properties of a reliable transaction system in the late 1970s and developed technologies to achieve them automatically.

In 1983, Andreas Reuter and Theo Härder coined the acronym ACID to describe them.

Atomicity : -

if one part of the transaction fails, the entire transaction fails, and the database state is left unchanged.

Example :-

a transaction to transfer funds from one account to another account. Making a withdrawal operation from the first account and a deposit operation on the second. If the deposit operation failed, you were not able to withdraw amount from the first account.

Logical Example :-

Suppose you are updating a table with 1000 number of rows. In middle you have cancel your query due to some reason. 

So the whole transaction will remain same and it will not effect to the table till the full transaction were completed.

Consistency :-

any transaction brings the database from one valid state(unique check numbers) to another.

a database tracking a checking account may only allow unique check numbers to exist for each transaction on what time transaction has performed.

Example :

Customer CIF number can give all tracking information about your account details. what when and what transaction you had performed.

Isolation : -

the execution of concurrent transactions brings the database to a state as if the transactions were executed serially, one by one

a customer looking up a balance must be isolated from a concurrent transaction involving a withdrawal from the same account. Only when the withdrawal transaction commits successfully and the teller looks at the balance again will the new balance be reported.

Example :-

After transaction successfully completed it should trigger new and current available balance in your both account (transfer account and withdrawal account).

Durability :-

once committed, the transaction remain so, even in the case of errors, power loss, or crashes.

A system crash or any other failure must not be allowed to lose the results of a transaction or the contents of the database. 

Example :-

Between the performance if your system get shutdown or crash it will not effect to the database when you are performing on production.