The high-resolution imaging capabilities of ALMA in the sub-millimeter regime allow us to study in astonishing detail the distribution of gas and solid material in planet-forming disks: the disks of gas and dust that orbit young stars during their formation. In this talk, I will discuss how do we trace the different disk components, how recent ALMA observations have characterized the underlying substructure of these protoplanetary disks, and how observing their substructures at multiple wavelengths allow us to infer disk properties. Finally, I will present recent results on searches for embedded planets that may cause the observed features in disks. All of these results gives us new insights into planet-forming disks in the era of ALMA.