PHP 5 introduced exceptions, a built-in mechanism for handling program failures within the context in which they occur. Unlike errors, which generally need to be fixed by the developer, exceptions are handled by the script. They represent an irregular run-time situation that should have been expected as a possibility and which the script should be able to handle on its own.
To handle an exception, it must be caught using a try-catch statement . This statement consists of a try block containing the code that may cause the exception, and one or more catch clauses.