Many audio/video monitors feature infrared light or "night vision" so you can see your baby on the monitor even when she's sleeping in a dark room. And some audio models feature a night light on the nursery unit that you can activate from the receiver. Other features may include adjustable brightness, and the ability to let you activate music or nature sounds to soothe your little sleeper by remote.
The main reason you’re going to need a baby monitor is to answer a simple, but time-honored, question: Why the hell is my baby crying? It’s only been in the last 30 years or so that parents have relied on the remote surveillance of their sleeping children. For the eons before that, it was a combination of natural, ear-piercing cries, and sleeping in the same yurt.
It really depends on what you feel most comfortable with. There are audio monitors that allow you to listen to any noise coming from the nursery, vital monitors that track sleep and breathing and video monitors that add sight to sound. Babylist parents overwhelmingly choose video monitors. The security of seeing what your child is up to—like if they’ve gotten tangled in their swaddle, pulled their diaper off or climbed out of the crib—can be worth the extra cost of a video monitor.