The term non-Euclidean geometry (also spelled: non-Euclidian geometry) describes hyperbolic, elliptic and absolute geometry, which are contrasted with Euclidean geometry. The essential difference between Euclidean and non-Euclidean geometry is the nature of parallel lines. Euclid's 5th postulate is equivalent to stating that for any given line l and a point A, which is not on l, there is exactly one line through A that does not intersect l.