Transmission Electron Microscopy (TEM) is a powerful imaging technique that uses a beam of electrons to visualize the internal structure of materials at a very high resolution. Unlike light microscopy, which uses visible light, TEM can achieve resolutions down to the atomic level, allowing scientists to study the fine details of samples, such as metals, biological specimens, and nanomaterials. In a TEM, electrons are transmitted through a thin sample, and the resulting interactions create an image that reveals the sample's composition and structure. This technique is widely used in fields like materials science, biology, and nanotechnology for research and development purposes.