Pattern
Pattern is an artistic or decorative design created by regular repetition of of compositional elements such as shapes, lines, colors, shadows, reflections, and motifs. Photos gain strength and interest if various elements form a repeating pattern, such as trees in a forest (lines), cars in a row (shapes), or ridges in a sand dune (texture).
A texture when enlarged become a pattern, and a pattern when reduced in size become a texture.
Zoom in to concentrate on patterns.
Advanced: When seeking patterns, try to find a composition where a single elements breaks it up, yet doesn't interfere with its integrity. In a case of repeated pattern in wallpaper, if that is all the viewer was seeing, they could become bored, or if it is a busy pattern, they could be confused. Placing an object such as a chair in front of the wallpaper will break up the monotony.
Rhythm
Visual rhythm is somewhat different in that there exists some directional movement in the repetition (as in a row of trees or undulating sand dunes).
You can enhance the rhythmic effect of many subjects by compressing perspective with a telephoto lens.
Number
Control the number of primary objects in a scene. An odd number creates a stronger composition than an even number of objects. An even number seems to divides the picture and confuse the viewer.