As to what it actually is, a lot of cones have a label  inside the bottom of the cone which should tell you something about it – at the least, whether it is wool or synthetic.

A lot of yarn for machine knitting is sold on cones like that, and it doesn't necessarily correspond to anything that is specified in hand knitting instructions.

A little by-the-bye that we couldn't expect an American to comprehend – to the British knitter, 2ply means very fine – think laceweight. Doesn't matter how many plies it has, to the elderly British knitter two ply is for shawls. That is all of a piece with our needle sizing – the numbers don't seem to match any particular measurement system, and some of the sizes don't exist in either metric or US sizes! We like to be different!

Thanks for posting that link TA - there are two woolshops in Penzance, and Knit Wits is the nice one.

It's not so much that the other one is bad, but they take things very seriously, and also keep the wool on racks behind the counter, so you have to point and ask - not my idea of how to sell yarn. Leave the stuff out on shelves where it can be stroked and petted and it will sell itself, is my idea. In Knit Wits you can prowl around to your heart's content, undisturbed, but they are always welcoming and ready for a jolly good natter.

King Cole are spinners who do basic good value yarns of all sorts, and you can buy it all over the place - online as well as in yarn shops.