Are long sizes for tall people?

[MrsBeaver]

I'm 5 ft 6" and a size 10 so buy regular size clothes online but if I wanted a dress which was slightly longer e.g. just below the knee whereas a regular sits on the knee, could I buy a size 10 Long or would it be long all over, iyswim? Or is it just the hem that is a bit further down?

Apologies if this is a daft question but it has stumped me!

They are normally long in the body too, and arms if long sleeved. But you could buy a size smaller and see if that evens out the size.