Fair Isle sweaters are named after a tiny island in the north of Scotland. The island is part of the Shetland Islands, famous for little fat, hairy ponies like this pair.
I don't know if they knitted their own sweaters or not, but they are fine examples of Fair Isle knitting.
Traditional Fair Isle patterns use only five colors and have only two colors per row. Unused colors of the alternating colors are "stranded" across the back of the piece.
'Fair Isle' has become a generic term for a style and is no longer limited only to sweaters knit on Fair Isle.
Sometimes people like me come along, chop up a vintage wool Fair Isle sweeater and use power tools to make a purse.
I call my washer, dryer and sewing machine power tools. Doesn't everyone?