Monocular A compound microscope with one eyepiece.
Dual-view A monocular microscope with a second viewing port. The second port can be used with an eyepiece for a second person, such as an instructor, or it can be used with an adapter and a video or still camera. The microscope has two viewing ports, but they are for two different people to use, each is used as a monocular viewing port
Binocular a microscope fitted with two eyepieces for viewing with both eyes.
Trinocular is a binocular microscope with a third, vertical viewing port. The vertical port can be used with an eyepiece for a second person, such as an instructor, or it can be used with an adapter and a video or still camera.