Rust panics are for bugs, not expected errors. When code panics (via panic!, unwrap(), expect(), or assertion failure), the thread unwinds by default, running destructors. I use panic! for invariant violations or \"this should never happen\" cases. For production, set panic = 'abort' in Cargo.toml to skip unwinding and reduce binary size. Panics can be caught with std::panic::catch_unwind, but this is rare; Rust prefers Result for recoverable errors. I reserve panics for programming errors and use Result for runtime errors. The key is intentionality: panics mean \"the program state is corrupt,\" while Result means \"this operation might fail normally.\"