From SQL Server CE to full-blown SQL Server, most databases are transactional databases A transactional database ensures consistency and integrity of data with transactions. A transaction consists of one or more SQL and queries or non-query commands. Hence Begin Transaction and End Transaction come into play:
1.Begin Transaction
2.Execute one or more queries or data-manipulation statements
3.If no errors occur then commit the transaction and End Transaction
4.If errors occur then rollback the transaction and End Transaction

With this, a partial transaction cannot be committed or persisted to the database

Internally, multi-user databases store and process transactions using a transaction ID or XID.