|Slow waves are ubiquitously observed in polar regions and active region fan loops. These waves cause periodic disturbances in intensity and are mostly identified from the alternate slanted ridges in the space-time maps. They are observed to have a range of periodicities from 3 to 30 minutes and are found to be rapidly damped. I will focus on their characteristic properties including damping. These characteristics allows us to perform coronal seismology. I will also discuss on the possibility of other wave modes and their role in coronal seismology. In the context of future mission like Aditya what kind of coronal seismology will be possible will be also addressed.