A pattern is a design in which lines, shapes, forms or colours are repeated. The part that is repeated is called a motif. Patterns can be regular or irregular.
Part of Art and DesignElements of art
Another way of creating patterns is to mirror the motif.
Motifs can be mirrored horizontally or vertically.
Swan, Rush and Iris (Walter Crane, 1875) is a wallpaper pattern than uses a mirrored motif.
The swans and the leaf pattern behind are arranged around a vertical line of symmetry creating a well-balanced image.