What type of lens has an adjustable focal length and adjustable focus?

A varifocal lens is characterized by its ability to provide an adjustable focal length, allowing the user to zoom in or out to capture a range of subjects or scenes, while also enabling adjustable focus to ensure that the image is sharp and clear at different distances. This flexibility makes varifocal lenses ideal for various applications in surveillance and photography where different fields of view and depths of field are required.

In contrast, a fixed lens does not allow for any adjustment in focal length or focus; it has a single, predetermined focal length which limits its versatility. Wide angle and telephoto lenses also have fixed focal lengths, meaning they cannot be adjusted dynamically, which makes them less adaptable compared to varifocal lenses. Wide angle lenses capture a broader view, while telephoto lenses allow for magnified views, but neither offers the capability to change focal lengths or focus as needed in real-time like a varifocal lens does.