Smart electromagnetic surfaces (SESs) are novel technologies that have gained significant attention in the field of wireless communication. They are expected to play an important role in the development of 5G, 6G and future wireless communication systems, that will be asked to fast data transfer rates, wide bandwidth, better coverage and almost zero latency. These goals can be achieved using mm-waves or sub-THz frequency bands, that present several advantages. On the other hand, they also suffer from some limitations as higher free space loss, higher building penetration loss, and strong interaction with obstacles along the propagation path. To overcome these drawbacks without increasing the complexity and the cost of the systems, recently the possibility of exploiting the environment in which the signal propagates as a further degree of freedom has been investigated.