The armillary sphere exhibits a series of rings that shape a celestial globe. These circles form its skeleton with the different coordinate grids (equator, ecliptic, meridian, and their parallels) to model the motions in the sky. Effectively, it is a mixture between a celestial globe and a 3D-astrolabe. The armillary sphere is based on the geocentric view: the virtual observer namely the Earth is placed at its centre. An outside horizontal ring represents the horizon. The touching points of the ecliptic and the equator rings are the spring and autumn equinox, respectively. When replacing the Earth by the sun, it can also serve as a Copernican system.

Armillary spheres were among the first complex mechanical devices with origins going back to antiquity. Some sources point to Eratosthenes as the inventor in 255 BC, however, he introduced it under the term "astrolabe". Due to the very rough instrumentation, differences between these seemed rather small. Other credits also meet Chinese astronomers in the 4th century BC. Their development was completed till the 1th century AD. The mathematician Zhang Heng (AD 78-139) is the first person known to have applied a hydraulics to rotate the sphere. Important improvements were made by Islamic astronomers in the 8th century, and further advances by Tycho Brahe (1546-1601). His elaborate spheres passing into astrolabes gained wide reputation. After the invention of the telescope the spheres became unpractical, so their role altered towards symbols of astronomical wisdom and luxurious decors.