The rule of thirds: one fine rule of photo composition

In the fields of photography, graphic designs and drawing-painting, the rule of thirds is one of the first lessons taught. So, this rule is also one which people throw at you to show they know more than you.  However, you must know the rule so that you compose photos properly. Later, when you are an expert, you can break the rule if that would lead to even better composition.

It has been found through research that our eyes are not focused at the middle of a drawing, painting  or photo but at some distance from it. The rule of thirds defines those places.

What the rule says is as follows: If you divide a driving into three parts horizontally and vertically, the main lines should be aligned with these lines and main objects should generally be at the intersections of these lines.

Look at the drawing here. The vertical object is aligned with the first vertical line. In a photo with a standing person, tree or tall building, you should try to keep these prominent  objects near the first or the second vertical line. Now see the horizontal line. This is aligned with one of the two horizontal dividers. You should keep the horizon, especially when it is near straight [e.g. sky over sea] on either the upper or lower horizontal divider. Now look at the round object. It is at one of the intersections. The rule of third says that prominent objects [e.g. the sun, a flower, a human head] should be at these intersections.