What does an unchecked exception class that extends the Exception class mean?

In Java, checked and unchecked exceptions are divided as follows:

• Checked exceptions inherit from Exception but not from RuntimeException. The compiler requires these exceptions to be handled in a try-catch block or declared in the method signature with throws.
• Unchecked exceptions inherit from RuntimeException or Error. They do not require explicit handling or declaration.

If an exception class extends Exception but not RuntimeException, it is a checked exception. This means that when using such an exception in code, it must be explicitly handled or declared, helping developers anticipate errors and improve program reliability.