A point is an exact position or location on a plane surface. It is important to understand that a point is not a thing, but a place. We indicate the position of a point by placing a dot with a pencil. This dot may have a diameter of, say, 0.2mm, but a point has no size. No matter how far you zoomed in, it would still have no width. Since a point is a place, not a thing, it has no dimensions.
Points are usually named by using an upper-case single letter. In the figure above, the points P,Q and R are shown. In this web site, points are shown either as a black dot or with a somewhat larger orange halo. This indicates the point can be dragged with a mouse.
In another branch of mathematics called coordinate geometry, points are located on the plane using their coordinates - two numbers that show where the point is positioned with respect to two number line "axes" at right angles to each other.
For more on this, see