A point is an exact location or position on a plane surface.
Points are dimensionless i.e, a point has no width, height or length.
We usually represent a point with a 'dot'(.).
(But how ever small a dot may be, it still has some length and breadth.It is therefore not actually a geometrical point. The smaller the dot – the more nearly it represents a point).
Points are denoted by capital letters such as A, B, X, Y, etc.
In the figure below, six points A, B, C, D, P and X are shown.
Real world examples: The mark made by the tip of a pencil or a ball-point pen on paper, the dots showing capital cities on a map etc.
A line is a set of points that extends endlessly in both directions i.e, a line has no end points.
A line is one-dimensional i.e, it has length, but no width or height. By a line, we normally mean a straight line (The other types of lines are curved and zig-zag).
Lines are uniquely determined by two points. Thus, we denote the name of a line passing through the points P and Q as , where the two-headed arrow signifies that the line passes through the unique points P&Q and extends endlessly in both directions. Sometimes lowercase letters like 'l', 'm', 'n' are used to denote a line.
In the figure below, three lines , and m are shown.
Real world examples: The half-way line in a football court, the lines of latitude, longitude and equator on a map etc.