The rule of thirds is a "Rule of Thumb" or guideline which applies to the process of composing visual images, designs, films, paintings and photographs.
Focal Point
The point at which rays or waves meet after reflection or refraction, or the point from which diverging rays or waves appear to proceed.
Pattern
It is repetition or alternation of one or more components to create a visual unit. Any visual element can be used to create a pattern. Repetition can be very powerful in creating a sense of order in composition. Alternation can create more complex patterns than those created by repetition alone. Examples of applications include architecture facades and interior decoration; textile and wallpaper design.
Leading Lines
Paves an easy path for the eye to follow through different elements of a photo.
Symmetry
It refers to a line that splits an object in half and, if both sides of the object are an exact mirror image of each other, then this object is said to be symmetrical.
Framing
It can make an image more aesthetically pleasing and keep the viewer's focus on the framed object.
Angles and perspective
Sense of depth or spatial relationships between objects in the photo, along with their dimensions with respect to the viewpoint.
Colour
Where in three primary colors (blue-violent, green, yellow...) are used to produce the color of subject photographed.
Minimalist
Within the art world it is considered an extremely subjective concept, leaving interpretation and meaning up to the viewers perception of the work.
Maximalist
It welcomes diverse aesthetics, excess, decadence and extravagance by breaking traditional design rules.
Curve
Remapping of image tonality, specified as a function from input level to output level, used as a way to emphasize colors or other elements in a picture.
Triangle
It is referred to to as the exposure triangle because when you adjust one element, another element must change to capture the same exposure.