A formal two-dimensional representation of a three-dimensional molecular structure
obtained by projection of bonds (symbolized as lines) onto a plane with or without
the designation of the positions of relevant atoms by their chemical symbols. A projection
formula which indicates the spatial arrangement of bonds is called a stereochemical formula or stereoformula. Examples of stereoformulae are
Fischer projection,
Newman projection,
sawhorse projection,
wedge projection and
zig-zag projection.