The document discusses equidistant lines and limiting lines in hyperbolic geometry. An equidistant line consists of all points that are equidistant from a given reference line, forming a hyperbolic circle rather than a straight line as in Euclidean geometry. A limiting line is the limiting form of a circle as one point on the circle and its tangent line at that point remain fixed while the circle expands without limit. Limiting lines are straight in Euclidean geometry but are limiting lines that are not straight in hyperbolic geometry.