Yes, #1 (Or super-fine, sock, fingering, baby) and embroidery yarn are the smallest that I know of. Try going to a craft store, they ususaly have a larger selection of yarn than any other store, like Walmart, kmart, etc, would have.
A slub is an imperfection in yarn, seen as a thickened portion of the cord. In an uniforn length of yarn, the slub stands out from the rest of the yarn. This gives fabrics woven with slubs some roughness to their texture.
"WYIB" stands for "with yarn in back," which means you should hold your working yarn behind your needles, as you do when you are executing the knit stitch.
the fabric weave by dyed yarn called yarn dyed fabric
Individual fibers are spun into yarn.
Yes, a small amount of wool yarn can be called a skein, especially if the fibre is rare and expensive, such as baby yak wool yarn.
Wool.
Wool
Loopy yarn can be yarn with loopsembeddedin the yarn lengths.
If they do, it's a rare disorder called "pica".
A coil of yarn may be called a hank or a skein. Yarn is typically sold in a ball or a skein. A hank is different in that it is a big loop of yarn that is twisted up for easy shipping.
Yarn that is a single strand is called single-ply or one-ply.
sometimes called 2 ply it is thin yarn which produces a thin fabric and is used for knitting lace (among other things)