Ans: A glacier is a large accumulation of crystallized ice, sediments, snow, rock debris, and ice-cold water. Glaciers are formed in the polar regions where the amount of ice formed every year is more than the amount of ice melted away. As the ice crystals accumulate along with the debris, sediments, snow, and water, they compress into large solid chunks of ice pellets.The common types of glaciers are listed below.Ice sheets or ice caps,Mountains or valleys,Continental glaciers,Outlet glaciers.