What lines have exactly one point in common?

Two intersecting lines have exactly one point in common. This is because lines are straight and extend indefinitely in both directions. Lines cannot bend, so they cannot intersect in more than one point.

More than two lines can intersect in one point only, and such lines are called concurrent lines. The point of intersection of such lines is called the point of concurrence. Intersecting lines must satisfy two conditions: they are coplanar, or lie in the same plane, and are not parallel to each other. Skew lines are lines that lie in different planes and can never have any point in common, meaning that they can never intersect each other.