The existence of starspots in other stars than the Sun has been known for more than five decades. The development of observing and analysis techniques that has occurred during the past couple of decades has enabled us to study the detailed surface temperature and magnetic field configurations on stars of different spectral types and ages. In this talk I will review what we have learned about the stellar surface structures using Doppler imaging techniques, and how these results compare with the direct images we have been able to obtain of the stellar surfaces within the last two years using near-infrared interferometry. I will finish the talk by discussing the possible future advances and how SONG can contribute to them.