Exception handling is a core feature in Java that allows you to manage unexpected problems, or exceptions, that can occur during program execution. Understanding how exception handling works internally helps you write more reliable and maintainable code.

Java uses a structured model for dealing with errors. When an error occurs, the Java Virtual Machine (JVM) creates an exception object and searches for code that can handle it. This process involves several key mechanisms:

• Stack traces: When an exception is thrown, the JVM records the sequence of method calls that led to the error, known as the stack trace; this helps you quickly locate the source of the problem;
• Try-catch blocks: You use try-catch statements to wrap code that might fail and define how to handle specific exceptions;
• Exception propagation: If an exception is not handled in the current method, it automatically moves up the call stack to previous methods until it is caught or the program ends;
• Method execution flow: When an exception is thrown, normal execution stops in the current method, and control is transferred to the nearest matching catch block;
• Memory effects: Exception objects are created in memory, and the stack trace uses additional resources; unhandled exceptions can lead to memory leaks if not managed carefully.

By mastering these mechanisms, you can prevent your Java programs from crashing unexpectedly and provide meaningful feedback when errors occur.