-Specimen or slide: The specimen is the object being examined. Most specimens are mounted on slides, flat rectangles of thin glass. The specimen is placed on the glass and a cover slip is placed over the specimen. This allows the slide to be easily inserted or removed from the microscope.
-a glass slide holding a specimen suspended in a drop of liquid (as water) for microscopic examination also : a specimen mounted in this way.
-The objective lens of a microscope is the one at the bottom near the sample. At its simplest, it is a very high-powered magnifying glass, with very short focal length. This is brought very close to the specimen being examined so that the light from the specimen comes to a focus inside the microscope tube.
-A light microscope uses focused light and lenses to magnify a specimen, usually a cell.That image then passes through one or more lenses to magnify it until it reaches the user's eye or a camera. Because light needs to pass through the sample, it must be either very small or very thin.
-Diaphragm or Iris: Many microscopes have a rotating disk under the stage. This diaphragm has different sized holes and is used to vary the intensity and size of the cone of light that is projected upward into the slide.
