What level of data protection is defined during transactions?

The isolation level is crucial in determining how transaction integrity is visible to other transactions during the process of execution. It specifically defines how and when the changes made by one transaction become visible to others, effectively protecting the data from being affected by concurrent transactions. This is particularly important in database management systems, as it helps to prevent issues such as dirty reads, non-repeatable reads, and phantom reads.

The isolation level allows developers to control the degree of visibility and concurrency among transactions, thereby ensuring that transactions occur in a way that does not compromise data consistency. It can be adjusted to suit the needs of the application, ranging from higher levels of isolation that offer more protection from concurrent access issues to lower levels that may allow for more concurrency but at the risk of potential data anomalies.