Explain the structure of the exception hierarchy in Java and its features

In Java, the exception hierarchy is based on the Throwable class, which has two main subclasses:

• Error — errors related to the virtual machine (e.g., OutOfMemoryError), usually not handled in code.
• Exception — exceptions that can and should be handled.

In turn, Exception is divided into:

• Checked exceptions — require mandatory handling or declaration in the method signature (e.g., IOException).
• Unchecked exceptions — descendants of RuntimeException (e.g., NullPointerException), do not require mandatory handling.

Features:

• Checked exceptions force the programmer to explicitly handle errors, increasing reliability.
• Unchecked exceptions usually signal programming errors.

Example:

try {
    // code that may throw IOException
} catch (IOException e) {
    e.printStackTrace();
}

Thus, the exception hierarchy helps structure error handling and differentiate between various problem types.