Protoplanetary Disks as seen by Interferometry

Protoplanetary disks encountered around young Pre-Main-Sequence(PMS) stars of low or intermediate masses are now observable bycurrent Near-Infrared (NIR) and Mid-Infrared interferometers.Taking also into account the progress done by millimeter arrays, interferometry is slowly but surely changing the knowledge we have of their physics. In this review, I show how these recent observations help to constrain the physical properties of both the very inner disks where planetary formation should occur and the outer disk where the reservoir of mass is located. I also illustrate this by presenting interferometric studies from a fewexamples such as AB Aurig