Standard gaiters are made of coated, waterproof nylon, sometimes with a breathable membrane (like Gore-Tex), and wrap snugly around your lower leg from your boot uppers to just below the knee, to keep snow out of your boots even in deep powder. When hiking or climbing peaks in spring or summer, you can encounter firm snow, but traditional gaiters can be too hot and heavy. Because you won't sink into firm snow, a gaiter that covers only your boot top to above the ankle is enough and useful in other seasons for hiking trails with lots of small stones.
Crampons are vital if there's ice on the trail. However, if you're winter hiking at lower elevations and expect to encounter only occasional patches of ice, you don't need full-on crampons. Instead, get a simple traction device that fits virtually any winter boot.
More points equal more grip: Basic 10-point, strap-on crampons are made for boots that flex when you walk and lack welts at the heel and toe for step-in crampons.
For general mountaineering and moderate ice climbing anywhere, get 12-point crampons that fit a variety of boots, including lightweight models with a heel welt but no toe welt.
Resources:
WWW.EHOW.COM
WWW.MTNTOOLS.COM
WWW.CLIMBING.COM
WWW.THEBACKCOUNTRY.NET