Electrons interacting with matter generates variety of signals that can be collected using dedicated detectors in a transmission electron microscope (TEM). The collected signals can be analysed to provide structural and chemical information of the material. 

The figure on the left is a schematic of the interaction and the signals that gets transmitted through the specimen are used for TEM imaging, diffraction and spectroscopy. The X-rays (EDX) produced by the material can also be collected for compositional analysis.