What is the difference between checked and unchecked exceptions?

Checked exceptions are exceptions that are checked by the compiler during compilation. The programmer is required to handle them using try-catch or declare them in the method signature with throws. Example: IOException.

Unchecked exceptions are runtime exceptions (RuntimeException and its subclasses) that the compiler does not require to be explicitly handled. They usually arise from programming errors, such as NullPointerException.

Thus, checked exceptions are intended for handling expected errors related to external factors, while unchecked exceptions are typically bugs in the code.