部品

1. Origins, structure, and basic meaning

• Structure: 部品 (ぶひん) is an individual component of a machine or product. It appears as a replacement and an item safeguarded.
• Basic usage: A broken component is replaced; small components are boxed to avoid loss.

2. Common pitfalls and similar expressions

• Part replaced for function and part stored for safekeeping
  • Both use 部品を, but 交換する restores function and 箱に入れる manages small items. They are not finished products.