In Go, errors are values returned from functions. The common pattern is: return `(result, error)` and check `if err != nil`.

• Report failures without exceptions.
• Keep control flow explicit.
• Add context to failures (wrapping) and handle them appropriately.

• error interface
• Custom errors
• Sentinel errors
• Error wrapping (%w)
• errors.Is / errors.As
• panic vs error
• defer for cleanup

• explicit /ɪkˈsplɪsɪt/: tường minh
• failure /ˈfeɪljər/: lỗi/thất bại
• context /ˈkɑːntekst/: ngữ cảnh