Java provides a hierarchy of classes that represent different kinds of exceptions. These classes are rooted in the java.lang package’s Throwable class, along with its Exception, RuntimeException ...

Thus, making an exception checked forces the programmer to pay heed to the possibility of it being thrown. An example of a checked exception is java.io.IOException.

In Java, exceptions are one of many structures that govern the control flow of a program. Specifically, they are unintended side effects of a program's normal execution.