The lazy man's dolly or tracking shot. Used effectively only in cases where speed is needed to grab the audiences' attention.
"We're losing light. Let's use a zoom lens instead of going through the difficulties of pre-planning and executing a superior tracking shot."
a Zoom lens is a lens on a camera (still and video both) to get a closer shot of the subject. There are lenses that have both optical zoom and digital zoom capabilities (optical zoom being the better of the two)
"I have a Kodak camera with a 10x optical zoom lens"