In organic chemistry wedge and dash, projections are used to represent three-dimensional structures of compounds on two-dimensional papers. There are three types of bonds in the wedge and dash notations as shown in figure:

1. Solid Lines: These lines show the groups or atoms connected in the plane of the paper.
2. Wedges: These are wedge-shaped bonds represents the connected group or atom coming out of the plane towards the viewer.
3. Dashes: Dashed bond represent the connected group or atom behind the paper or away from the viewer.