巡回 and 往復: the area covered and the return journey
Compare rounds through a building or villages with daily travel between home and a station, separating the area covered from travel out and back.
Rounds through a building and villages
巡回 (じゅんかい) describes rounds through an area or places. 「警備員が夜の建物を巡回した。」 says that the guard patrolled the building at night.
「移動図書館は三つの村を順番に巡回する。」 says that the mobile library visits three villages in turn. 順番に gives the order of visits, without reporting that all three visits have already finished.
Travel out and back between two points
往復 (おうふく) describes going out and returning. 「家と駅の間を毎日歩いて往復しています。」 says that the speaker walks back and forth between home and the station every day.
This example supplies two points, home and the station, and the relationship of going and returning. 毎日 marks the daily repetition of that travel.
Comparing the structure of the movement
The 巡回 examples focus on the building covered by the patrol and the three villages visited in turn. The 往復 example focuses on the outward and return journeys between two points.
Do not define 巡回 as necessarily following a closed circle back to the start or as movement only for inspection. Include the mobile library example when comparing the area covered with the return relationship of 往復.
Does 「移動図書館は三つの村を順番に巡回する。」 also tell you the route back to the starting point?
Show the answer and why
No. It says that the three villages are visited in turn, without supplying a route back to the starting point.