A compound microscope is an optical instrument that uses multiple lenses to magnify small objects. It is called a "compound" microscope because it uses two or more lenses to produce a magnified image of the specimen. The lenses work together to magnify the image and allow the viewer to see details that would not be visible to the naked eye.
A compound microscope typically consists of two sets of lenses: the objective lens and the eyepiece lens. The objective lens is located near the specimen being viewed and produces a magnified image that is then projected to the eyepiece lens. The eyepiece lens is located at the top of the microscope and further magnifies the image produced by the objective lens.
In addition to the lenses, a compound microscope also includes a light source, a stage on which the specimen is placed, and focusing knobs to adjust the focus of the lenses. Modern compound microscopes often include additional features such as digital cameras for capturing images and software for image analysis. Compound microscopes are used in a wide range of scientific and medical applications, from biological research to medical diagnosis.