Tangent Line:A tangent line is a straight line that touches a curve at only one point, without crossing it. It represents the instantaneous direction of the curve at that point.
Radius of Curvature: The radius of curvature is the radius of the circle that best approximates a curve at any given point. It indicates how tightly or loosely the curve bends.
Osculating Circle: An osculating circle is a circle that has exactly one point in common with a given curve and shares both its tangent line and curvature with that point on the curve.