What's the difference you ask?
You’re bound to have one in your wardrobe, it’ll have buttons going all the way to the top of the shirt.
But then Polo happened.
The traditional polo kit of the 19th century, was a formal collared shirt worn on horseback as players attempted to skilfully strike the ball (or opponent) with the long side of the mallet head.
The only glaring issue, was that a player's collar would flap up into his face when a horse increased speed – leading to all sorts of horse pile-ups.
To combat this impediment, the players had taken to stitching small buttons onto their shirts, securing the collar in place.
And born was the b-down'
Because God forbid we remove the collar entirely.
Crucially, it means the collar is able to be fastened down to the shirt. When you arm yourself with the button-down feature, it’ll sharpen the overall look while broadening the shoulders.
So there you have it... Now enjoy the show and play nice gentlemen.