Division of the field
In heraldry, the field (background) of a shield can be divided into more than one area, or subdivision, of different tinctures, usually following the lines of one of the ordinaries and carrying its name (e.g. a shield divided in the shape of a chevron is said to be parted "per chevron"). Shields may be divided this way for differencing (to avoid conflict with otherwise similar coats of arms) or for purposes of marshalling (combining two or more coats of arms into one), or simply for style. The lines that divide a shield may not always be straight, and there is a system of terminology for describing patterned lines, which is also shared with the heraldic ordinaries. French heraldry takes a different approach in many cases from the one described in this article.
Common divisions of the field
Common partitions of the field are:
parted (or party) per fess (halved horizontally)
party per pale (halved vertically)
party per bend (diagonally from upper left to lower right)
party per bend sinister (diagonally from upper right to lower left)