Refers to a soldier or military personnel assigned to guard a place, person, or object. Often used in military or formal contexts.
Two guards were standing at the palace gate.
衛兵が交代する時間だ。
It's time for the guards to change.
Red Guards
guardhouse; guardroom
bodyguard; personal guard
Compound of 衛 (guard, protect) and 兵 (soldier). The exact historical derivation is uncertain, but the word has been used in military contexts since at least the Meiji period.