| Transition disks are protoplanetary disks with inner dust cavities and they may reveal an intermediate step of the ongoing disk dispersal process, where planet formation might happen. The recent gas and dust observations of transition disks have given major support to the idea that clearing by planet(s) is the primary cause for the origin of the cavities in transition disks.
In this talk I will present gas and dust evolution models of transition disks, and I will show the different structures that disks can have (rings, vortices, spiral arms) when a planet or multiple planets are embedded in the disk. Moreover, I will connect these results with recent SPHERE/VLT and ALMA observations of some of these disks, e.g. J160421, HD 100546, SR 21, and HD 135344B.