There are many different types of microscopes in the world. Antony Van Leeuwenhoek was the inventor and the first man to create and use a microscope. The microscope he invented was called the single lens microscope. It had the magnification power up to 270 x. To make the microscope work correctly, it takes very little skill because it is not complex. What you would do to use it is very simple. Just put a slide on the stage and secure it under the stage clips, making sure the slide is centered. Next, look through the lens and you will see your object magnified. It only had one lens, so it was called the single-lens microscope. Its convex glass lens was attached to a metal holder, and you could focus it with using screws. To increase the power of a single-lens microscope, you have to reduce the focal length. Another microscope is the compound microscope. It was invented by Robert Hooke in 1665. Unlike the single-lens microscope, it had two or more lenses, so the image magnified by one lens could be further magnified by more lenses. The eye piece is one of these lenses. It has a magnification power of ten times. You use it by adjusting the coarse adjustment knob and if the microscope has one, the fine adjustment knob. This microscope was invented because after reducing the diameter of the single-lens microscope so much, it became hard to see through. The last microscope is the SEM which stands for the scanning electron microscope. You use it by coating samples with gold. The samples are then placed in the microscope vacuum column. Then the air is pumped out of the column. The S.E.M. creates the magnified images using electrons instead of light waves. It also shows very detailed three dimensional images at higher magnifications than possible with a light microscope, but it shows the image in black and white instead of in color. That might be a disadvantage because you might want to see what the object looks like in color. These are three very different types of microscopes.

Compound microscope

E.N. Micro 22222 http://www.iki.kfki.hu/radchem/instruments/sem.jpg
S.E.M. Microscope

Single lens microscope.

S.E.M. microscope
Sinle Lens Microscope