The monorail part is a central guide rail that the vehicles use for most of their routes, though the Nancy ones run for part of their routes without the guide rail as an electric trolleybus.
Bombardier Guided Light Transit - Wikipedia
Guided Light Transit (GLT, French: Transport sur Voie Réservée or TVR) was the name of guided bus technology and associated infrastructure designed and manufactured by Bombardier Transportation (now Alstom). It was installed in two French cities: Nancy and Caen. The Caen system was closed in 2017 and replaced by conventional trams, while the Nancy system was closed in March 2023 and is to be replaced by trolleybuses.The Translohr - Wikipedia system is a similar one, but more widely used. It and the GLT / TVR are Rubber-tyred tram - Wikipedia