Any problem with a DML statement, such as an insert statement missing a required field on a record.

Exception Class and Built-In Exceptions

An exception denotes an error that disrupts the normal flow of code execution. You can use Apex built-in exceptions or create custom exceptions. All exceptions have common methods.

All exceptions support built-in methods for returning the error message and exception type. In addition to the standard exception class, there are several different types of exceptions.