Im sorry if Im not asking this in the right section, but is dk yarn the same as fingering weight or sock yarn?
They are different weights, this site explains better Knit Picks
I think in most cases, dk is lighter than worsted, about 5.5 or 6 stitches an inch. Fingerling and sock are lighter, 7 or 8 stitches an inch, I think. All fingerling is not sock - you wouldn’t want something with no stretch in it, like straight cotton, for socks, but you can use dk, or anything else for that matter, to knit socks, just be aware the socks might be bulkier with heavier yarn.
I tend to get confused when some sites or manufacturers break their worsted into light, regular, and heavy … most of the time I ignore the labels, and just look to the suggested gauge.