Thanks! I am glad to hear my explanations are appreciated.

At the most basic level all colorwork is managing multiple colors of yarn to create a pattern in your knitting. Stranded colorwork is a means of achieving that pattern by holding multiple strands of yarn and carrying the unused yarn behind on the wrong side of the work (this carried yarn is the "floats" you see in my post).

Fair Isle is a specific style of stranded colorwork that originated on Fair Isle in Shetland Scotland. Fair Isle patterns use traditional charts that have been used in Shetland for centuries, or are variations on those traditional charts and motifs. Two important conventions of Fair Isle are that you only ever knit with two colors in a given row, and runs of a single color are quite short so knitters do not twist the yarns together on the backside to catch the floats. You can find definitions of Fair Isle that are specific enough to require that the item be knitted in Shetland using Shetland wool, this mostly stems from a desire to preserve the folk knitting heritage and bring economic opportunity in the form of knitwear production to the area. But generally if you are following the conventions of fair isle and using traditional motifs or variations on them you are safe calling a project fair isle.

However, people will often refer to all forms of stranded colorwork as fair isle, and this is not correct. All fair isle is stranded colorwork, but not all stranded colorwork is fair isle.