Question

what is thee difference between SEM and STM.

Answer 1

SEM is Scanning Electron Microscope, STM is Scanning Tunneling Microscope.

SEM has a resolution of nanometers (nm), while STM allows seeing objects around 0.1 nm in size. SEM uses electron beam to "light" the objects and get their images, STM uses a phenomenon called quantum tunneling to create images.