Compound microscopes are advanced optical instruments designed to magnify small specimens that cannot be seen with the naked eye, using multiple lenses for high-resolution observation. They are the most common type of microscope used in laboratories and can achieve magnifications from about 40x to 1000x or higher. By combining an objective lens (close to the specimen) and an eyepiece lens (close to the observer’s eye), they provide clear and detailed views of biological and material samples.