Vitola is a general name for the specific size and shape of a cigar. A vitola can also be referred to as the cigar 'format'.
While there are standard and generally accepted vitola names, like Robusto which measures 5"x50rg, manufacturers often create their own unique vitola names for their brands.
In the United States, the length of the cigar is measured in inches while the diameter, or ring gauge (rg) of the cigar, is measured in 64ths of an inch ("). Cuba and some European and Asian countries use the metric system.