The document discusses microscopy and the microscope. It defines microscopy as observing small objects using a microscope that are invisible to the naked eye. It provides a brief history of microscopy from the 17th century to recent developments. It describes the basic parts and types of microscopes, including light microscopes, polarizing microscopes, and electron microscopes. It explains that the usefulness of a microscope depends on its ability to magnify and resolve detail, with the resolution of light microscopes being about 0.2 micrometers.