効用

1. Origins, structure, and basic meaning

• Structure: 効用 (こうよう) is a noun for the practical utility or benefit produced by something.
• Basic usage: 道具の効用を確かめる tests a tool's usefulness; 休憩の効用を実感する recognizes the benefit of a break.

2. Common pitfalls and similar expressions

• Practical utility and experienced benefit
  • A tool favors utility, while a restorative break favors benefit; the preceding の phrase identifies the source of the effect.