How does error handling work in Go?

Go handles errors by returning them as values rather than using exceptions. Functions that can fail return an error as their last return value: f, err := os.Open("file.txt"). The caller checks if err != nil { ... } immediately. The built-in error interface requires only one method: Error() string. This explicit approach makes error paths visible in the code and forces the programmer to consciously decide how to handle each failure. Custom error types can carry additional context beyond a simple message.