In manual-commit mode, applications must explicitly complete transactions by calling SQLEndTran to commit them or roll them back. This is the normal transaction mode for most relational databases.
Transactions in ODBC do not have to be explicitly initiated. Instead, a transaction begins implicitly whenever the application starts operating on the database. If the data source requires explicit transaction initiation, the driver must provide it whenever the application executes a statement requiring a transaction and there is no current transaction.