All conventional light / optical microscopes consist of the following parts:
Eyepiece Lens: this is the lens we look through, it usually has the power ranging from 10X to 40X
Arm: connects the base with eyepiece lens and turret.
Base: Well, its the "base" of a microscope.
Illuminator: The light source located at the base of a microscope, powered by electricity or a mirror, reflecting external natural light.
Stage: The platform with clips where you place secimen.
Revolving Nosepiece or Turret: The rotating part of a microscope with objective lenses.
Objective Lenses: There are usually 3 or 4 of them, located on the turret. Objective lenses have the following magnifications: 4X, 10X, 40X and 100X. The longest lens has 100X of power. The lenses are normally achromatic, parcentered and parfocal.
Condenser Lens: They focus the light beam onto the observed object. Some microscopes are equipped with the Abbe condenser lens which moves up and down.