In that case you have a dropside van, based on the same cab and chassis but with sides that fold down for easier loading and unloading.

In use: https://commons.wikimedia.org/wiki/File:Bairon-FR-08-chantie...

https://commons.wikimedia.org/wiki/File:Mercedes-Benz_Sprint...

(Can an American tell me what these vehicles are called in the USA?)

> (Can an American tell me what these vehicles are called in the USA?)

Flatbeds.

I think in America we'd just call that a "flat bed truck" or something, which is a catch all for those that do indeed have flat beds as well as these with short sides around the bed.

That got me there with a little extra searching. "Flatbeds with side gates."

Here they are very common on construction sites for the messier work (building roads, railways, walls, roofs, forestry etc) but normal vans with a roof are more common for the cleaner work (plumbing, electrics, painting, carpentry etc).

Most van models are offered commercial version that has a separation between the cab and the cargo space, at least in Europe.