Basically meaning ‘workshop’ in French, Atelier is used to describe a studio, especially one where an Artist is training students or where assistants are working under the supervision of an Artist.

An Atelier libre – free workshop – is used to describe a studio where Artists meet to work together without tuition but to share resources, such as a Life Model, or just to bounce ideas off each other.

The photo is of an Atelier de Peintre or 'Painter's Workshop' at an Ecole des Beaux-Arts - School of Fine Art.