What does the term 'heliocentric' mean?

The term “heliocentric” means Sun-centered. It describes a model in which the Sun is treated as the central body of the Solar System, with Earth and the other planets orbiting it.

The word combines Greek roots: helios means “Sun” and kentron means “center.” Nicolaus Copernicus presented the best-known early modern mathematical heliocentric model in the 16th century, challenging the older geocentric system associated with Ptolemy, which placed Earth at the center.

Heliocentric does not mean that the Sun is the center of the entire universe. Modern astronomy places the Sun near the center of our planetary system, while the Solar System itself orbits the center of the Milky Way. Another common mix-up is confusing heliocentric with “solar-system-centered”: the Sun is not perfectly stationary, because planets and the Sun orbit their shared center of mass.