A transmission electron microscope (TEM) is a powerful tool used to observe the internal structure of very small samples at high magnification. It works by transmitting a beam of electrons through a thin specimen, allowing scientists to see details at the atomic level. TEMs are essential in fields like materials science, biology, and nanotechnology. The images produced by a TEM are highly detailed and can reveal information about the arrangement of atoms and the composition of materials. This technology has advanced research in various areas, including the study of viruses, metals, and semiconductors, contributing significantly to our understanding of nanostructures and cellular biology.