Antonio G. Di Benedetto has an in-depth look at the little buttons on the underside of the Apple Watch that make swapping bands so easy:
While I often prefer a universal solution over a proprietary connector, here’s the thing — Apple’s band release button beats the hell out of fiddling with little spring bars and jeweler’s tools. Instead, you just press a near-invisible button, slide your band out, slide another one in, and get a lovely audible click as it locks in. No fuss, no muss; just a simple swap for a different visual vibe to match your style and wardrobe.