DIVISION OF GUITARS ACCORDING TO THE NUMBER OF STRINGS
Six-stringed
The vast majority of guitars have six strings.
Twelve-stringed
Modified jumbo or western guitar. The intention is primarily a more pronounced, more intense sound. Tuning is the same as the six-string guitar, except that each string is "double" (2x E, 2x H, ...). The most common usage of twelve string guitars is in country and bluegrass style.
Others
Sometimes we also encounter other strings. Of course, experiments are not bound to the limits. E.g. seven or eight-beat guitars have added bass strings for a larger range of tones.