Light is just one form of electromagnetic radiation, or electromagnetic waves. These waves are all around us and come in many sizes. The largest electromagnetic waves, with wavelengths from a few centimeters to over 100 meters are called radio waves. Light is essential to our health and wellbeing; it regulates our sleep-wake cycle. It can also help with our daily routines: from bright functional light to keep you energized and up your concentration level, to warm light that creates a cozy ambiance that helps you to unwind in the evening.