So now that we know that electron microscopes are very powerful magnifying tools, in this video we're going to talk about some different types of electron microscopes. And really there are two main types of electron microscopes that you all should know that are used to study both external and internal cell structures. We've got these two electron microscopes shown down below. The first is going to be the scanning electron microscope or the SEM for short. The scanning electron microscope or SEM is specifically used to visualize external cell surfaces and structures on the outside surface of cells. Now, the second type of microscope that you all should know is the transmission electron microscope or the TEM for short. The transmission electron microscope or TEM is specifically used to visualize internal cell structures and organelles. Let's take a look at our image down below to better understand this. Notice on the left-hand side over here, we have this really fancy piece of equipment, and this piece of equipment here is a scanning electron microscope. It's a very, very fancy and a very, very expensive microscope that's used to visualize external cell structures. SEMs are used to visualize external cell structures on the surface of cells. Over here on the right-hand side of the image, we have another fancy piece of equipment. This fancy piece of equipment here is a transmission electron microscope or a TEM, another incredibly expensive piece of equipment that's used to visualize, as this image shows over here, internal structures and organelles within cells. Moving forward, we're going to be talking about lots of different cell structures, and it's important to know that scientists can actually visualize these cell structures using either SEMs, if it's external cell structures, or TEMs if they are internal cell structures. This here concludes our introduction to the different types of electron microscopes, and we'll be able to get some practice applying these concepts in our next video. So I'll see you all there.