What exactly is the difference between a compass vs inclinometer?
It's all about what you are trying to determine. A compass shows you directions (north, south, west, east), be it in a dessert, in the middle of the seas, or in the midst of a snowstorm. An inclinometer (also called clinometer, tilt indicator, gradient meter, and level gauge amongst others), though, is used to measure angles of a slope (usually of an incline or the ground's elevation). This is handy when plotting a hiking trip when driving a truck in mountainous areas, and, of course, when doing construction surveys.
As time goes on we are seeing more and more technology in all-in-one devices. Most total stations (robotic or otherwise) can do both jobs. However, when you're just running over some details and want to quickly check your numbers out, it's a whole lot easier to whip out a compact compass and/or inclinometer. Check out these handy devices. No tripod setup needed!