Engineer ("ingénieur") is both a diploma, a status, and a title.
The diploma is regulated by a committee that endorses curriculum for colleges so that they can deliver an engineering degree. It indeed requires some specific training, and not all schools have the endorsement. There _is_ a difference between "I have an MSc in X" and "I am an engineer in X". I think this is what you are referring to.
The status can be earned by having the diploma or getting a recognition of skill by experience. It's usually useless in private companies, but opens the door to better social security in public and institutional services.
The title (as in job title) is unregulated and can be given to anyone.