Ok this is really dumb but do normal contractions tighten the belly exactly the same as BH do??? Or are they more specific to one are of the belly?????

I get BH all the time and my whole tummy goes rock hard from top to bottom but I can't remember if this happened when I was in labour with Iz. The answer is probably so obvious - "duh Tan of course they do" but I thought I'd ask anyway.....