What is a practice or pattern that is a performed in a specific manner

Hi,

A pattern is a discernible regularity in the world or in a manmade design. As such, the elements of a pattern repeat in a predictable manner. A geometric pattern is a kind of pattern formed of geometric shapes and typically repeated like a wallpaper design.

This is what i think 

~Girlygir101~

Catac, dry land,and lizards

Answer volcanic outgassing;