"Product attributes" are concepts like size or color and their respective attribute values" would be s,m,l and r,b,g.
You can group together size and color into an "attribute set". You assign an "attribute set" for any item in the Stock, Product screen. (It is located under Category and above Tax Category.) If you did everything right, you can (while in the sales screen) tap on that item. When it appears in the sales section, on top, you may tap on the manilla tag and select the attributes.
Check ou the video below.