in general, operations made in a transaction cannot be seen by other users until the transaction is committed, and thus, when you rollback the transaction, the data other users see is not affected. Many users could open transactions on the same table, but they cannot modify the same data, because when a user modifies some record, the record gets locked, and the lock is released until the transaction is committed (or rolled back), so, many users can simultaneously modify data in the same table, but no the same data, and thus, when one of them rollback his transaction, only the changes made by him are rolled back, and since nobody else could have modified the same data, there is no conflict when rolling back, and the data remains integral.

in general, operations made in a transaction cannot be seen by other users until the transaction is committed, and thus, when you rollback the transaction, the data other users see is not affected. Many users could open transactions on the same table, but they cannot modify the same data, because when a user modifies some record, the record gets locked, and the lock is released until the transaction is committed (or rolled back), so, many users can simultaneously modify data in the same table, but no the same data, and thus, when one of them rollback his transaction, only the changes made by him are rolled back, and since nobody else could have modified the same data, there is no conflict when rolling back, and the data remains integral.