Ice climbing evolved from equipment used by alpine-style mountain climbers to negotiate icy patches at high altitude. Today, most ice climbers use crampons and ice axes to drag themselves up steep glacial walls and frozen waterfalls. Ropes, screws and other safety features are also part of the equation, and helmets are a necessity because of the danger of falling ice.
Glacier-walking is a tamer cousin of waterfall climbing. It may require special equipment like crampons, but is usually a gentler activity (although glaciers are often part of protected areas, so a guide is necessary). More-vertical ice climbing comes with a steep learning curve, but the sport has become quite accessible, with some waterfalls and glaciers offering challenges for both novices and expert climbers.