This is the original banjo, used in bluegrass music when fiited with a resonator, and in old time music with an open back. Various sizes. See 5 string banjo.
A four string version of the 5-stringer. See four string guitars and banjos
A shorter scale version of the plectrum banjo. See four string guitars and banjos
Used in banjo orchestras. Tuned like a cello:
Rare, used in some banjo orchestras. Versions exist played like a guitar, and like an upright bass.
Tuned and played like a guitar.
A small, eight-stringed four-course instrument strung and tuned identically to a neopolitan mandolin.
Almost any plucked instrument has been produced with a banjo body at some time!