関係者

1. Origins, structure, and basic meaning

• Structure: 関係者 (かんけいしゃ) is a person involved in a matter or personnel authorized because of that connection.
• Basic usage: 工事の関係者 identifies someone involved in construction; 関係者だけが入れる restricts entry to authorized personnel.

2. Common pitfalls and similar expressions

• Involved person and authorized personnel
  • The construction context stresses involvement; the restricted room stresses authorization, with だけ limiting who may enter.