So I know that quandles are associated with knot theory, etc. but what are "shadow colorings" ? on a broader context, can someone plz give me a simple definition of a "knot invariant" and a "quandle" ? and what does this have to do with "racks" ? sorry, all this esoteric language is really confusing. it would be awesome if someone could give me a dumbed down version of knot theory, as an introduction to it. im kinda interested in this subject, just i need to understand the basic meanings/definitions first..thanks! i tried reading a bunch of research papers..though I failed epicly. too much vocab. and concepts that I did not understand. for example, "isotopy" and "cocycle" and "quandle coloring"