The difference in yarn sizes??

[crunchycrafts]

ok so what's different between aran and worsted and what about dk? Ive been knitting for a while but im not sure i know why they are different are they really different sizes?

i mean im not totally dumb i know that yarn comes in the diffrent sizes fingering bulky worsted but i just dont know are aran and worsted the same and how much diffrent is dk from worsted

[flapjack]

Aran and worsted are pretty much interchangeable- worsted's slightly thinner, but there's not much in it. DK is slightly finer- if you can imagine it, aran you knit on 5mm needles, sock weight on 3mm and DK is right in the middle with typically 4mm
Any help?

[crunchycrafts]

a little yeah - thanks