部队 (bùduì) refers to a specific military unit, troops, or armed contingent — narrower than 军队 (jūnduì), which denotes the armed forces as a whole or the military as an institution. Unlike 兵 (bīng), which emphasizes individual soldiers or the army as a collective, 部队 focuses on the organized group. 队伍 (duìwu) can also mean 'troops, military unit,' but it is much more common in non‑military contexts like a queue or procession.