Explain checked versus unchecked exceptions and the modern argument for preferring unchecked in many designs.

Checked exceptions (subclasses of Exception, not RuntimeException) must be declared or handled and are meant for recoverable conditions; unchecked (RuntimeException) signal programming errors or unrecoverable states and need no declaration.

Many modern frameworks (Spring) favor unchecked exceptions because checked exceptions force boilerplate, leak across abstraction layers, and don't compose with lambdas/streams (functional interfaces don't declare them). The trade-off is checked exceptions document recoverable failures at compile time, which is genuinely valuable for true business-recoverable cases like IO.