Terahertz waves are a type of electromagnetic radiation that falls between microwave and infrared frequencies, specifically in the range of 0.1 to 10 THz. They have wavelengths ranging from 0.03 to 3 millimeters. Terahertz waves are unique because they can penetrate various materials, making them useful for imaging and sensing applications. These waves are increasingly being explored in fields like medical imaging, security screening, and communications. Their ability to provide high-resolution images without harmful radiation makes them a promising technology for non-invasive diagnostics and material analysis.