Learn Photography
Guideline of Thirds would be a better name than Rule of Thirds.
Rule implies that the principle must be used for every photograph.
But, it's a guideline that's often used, but not always.
Many, but not all, photographs benefit from the application of the Rule of Thirds.
Draw an imaginary tic-tack-toe grid across your photograph.
Important elements of the photograph should be placed on or along the lines, or at the intersections of the lines.
In Photoshop Elements, you can make a Rule-of-Thirds grid across your photograph.
Then, check your composition, and crop if necessary.
Go to Edit > Preferences > Grid (Windows) or Photoshop Elements > Preferences > Grid (Mac).
Select a color other than black, if you wish.
Change the Gridline every value to 33 percent, and Subdivisions to 1.
For example, compare the original version . . .
. . . with this cropped version.