A line, or straight line, is, roughly speaking, an infinitely thin,
infinitely long, straight geometrical object, i.e. a
curve that is long and
Given two points in
Euclidean geometry, one can always find
exactly one line that passes through the two points; the line provides the
shortest connection between the points.
Three or more points that lie on the
same line are called collinear. Two different lines can intersect in at most one
point; two different planes can intersect in at most one line.