Rule of thirds is a composition rule that is used by many photographers, On a camera you can enable a 3x3 grid, each rectangle is perfectly equal in size, when using the rule of thirds, the subject of your picture should be along the right line or left line.
The Photo/Diagram to the left shows this.
My Rule of Third Pictures
Subject is on the Left Line
The Clock is the Subject and is on the right line
Subject is on the Left Line
The Candle is the subject it is on the left line
Subject is on the Left Line
The Pencil is the subject it is on the left line
Rule Of Thirds used, Tree, Grass, Sky Accurate Colours, Correct Aperture
Rule Of Thirds used, Person, Sky, Trees Accurate Colours, Correct Aperture
Rule of Thirds Used Inaccurate Colours, Aperture Too High
Rule of Thirds Used Inaccurate Colours, Aperture Too High