必要

1. Origins, structure, and basic meaning

• Structure: 必要, read ひつよう, describes something as required or needed to satisfy a condition or accomplish a purpose.
• Basic usage: It states that identification is required for an application or modifies selected tools as 必要な道具.

2. Common pitfalls and similar expressions

• A requirement and needed items
  • It applies when identification is required for an application and when only needed tools are selected. Judging something necessary is distinct from already possessing it.