If your particular location on the Earth is selected as your point of reference, the point directly overhead is the zenith. The opposite point, below the Earth, is the Nadir. At right angles to these is a plane which is called the Horizon: the extension to the Celestial circle of the line which, from the point you occupy, intersects earth and sky. These established, you have a Vertical circle running from the Zenith, through a middle point between East and West, to the Nadir; and similar circles running through each degree all around the horizon. The distance of each of these circles from your circle is measured by the arc at which the circles intersect at the Zenith - termed Azimuth. Parallel to the Horizon are Parallels of altitude. These are measured by the arc separating the radius of your horizon from a line drawn from the same center to a given parallel of altitude.
The trouble with this system is that a location based upon your position fails to describe the same location as viewed from any other point on the Earth's surface.
