For some odd reason, 'plaits' is pronounced as 'platts'. Just as 'plaid' is pronounced 'pladd' or, of course, 'tartan'. When I was in primary school a lot of us had what we then called 'pigtails' - ie two plaits, one on each side. Mine were singularly unsuccessful as I had then, as now, very fine hair. 'Braids' nowadays is used to describe the elaborate designs in which many African/Caribbean girls - even men - wear their hair and which, I'm reliably informed, can take many hours to accomplish! this is how to do a French plait.