What does it mean if handwriting is defined as "Boustrophedon"?

Most languages are written either left to right, as in most European languages, or right to left, as in Hebrew or Arabic. But in ancient times, a reasonably common variant on this, known as Boustrophedon, was the alternation of lines in orientation. For instance, it was used in some ancient Greek, also in Etruscan. It has also been found on artefacts from the Pacific Island of Rapa Nui.

The word has an interesting derivation. It comes from ancient Greek words referring to the turning of a ploughing ox.

Although, nowadays, its use as an actual form of handwriting is extremely rare, though not entirely extinct, the basic principle is still used in spheres as diverse as town planning, and dentistry. The Atlantean language constructed for the 2001 film "Atlantis: The Lost Empire" is also written in Boustrophedon.