What is a short and complete shingle definition?

A shingle is a lightweight bitumen roofing material composed of a reinforcing material (usually a fibreglass mat) embedded in asphalt, with a coating finish made of granules. 

The bottom of each asphalt shingle is cut for aesthetical purposes. Several shapes are available: rectangular, beaver, triangular, hexagonal...  

They must be installed on a full deck (not a discontinuous structure), waterproofed protected by a bitumen membrane. Their installation is made recovering flat and uncut part of the previous shingle. See Bardoline roofing shingle fixing guide to know more about shingle installation.