Why are transactions needed in a database?

Transactions in a database are necessary to ensure the integrity and consistency of data when performing multiple related operations. They allow:

• Guarantee that all operations within a transaction are either fully completed or not executed at all (atomicity).
• Provide isolation of concurrent transactions so they do not interfere with each other.
• Maintain a consistent state of data (consistency).
• Ensure durability of changes after a transaction is committed.

For example, when transferring money between accounts, it is important that the debit from one account and the credit to another happen together — if one operation fails, the other should not be applied. Transactions enable achieving this.