What is a fishermans knot used for? is their any other names for it??

Question

i also need to no what a sheep shank is used for

a prusik knot

alpine butterfly

a figure eight on the bight

and a monkeys fist

Answer 1

to tie a lure on      

rapala knot

Answer 2

To tie your line to your hook or lure.  There are several types of knots but none really have a different name it just depends on the bait you are using and the persons preference.