Refers to a longer or indirect route, either physically or figuratively.
We had to take a detour because of construction.
遠回りしても、景色のいい道を行きたい。
Even if it's a roundabout way, I want to take the scenic route.
Because of construction, I went home by taking a detour through the park.
This road looks like a shortcut, but it actually turns out to be a detour.
To avoid the traffic jam, I went to the station by taking a longer route.