They are large masses of snow, recrystallized ice and rock debris that accumulate in great quantities and begin to flow outwards and downwards under the pressure of their own weight. Glaciers form when yearly snowfall in a region far exceeds the amount of snow and ice that melts in a given summer. In this way, massive quantities of material accumulate in relatively small periods of geologic time.
1 5 1
Glacier is a body of dense ice  moving constantly under its own weight. Siachen Glacier is an example of this.
A huge mass of ice slowly flowing over a land mass, formed from compacted snow in an area where snow accumulation exceeds melting and sublimation.
the slow moving of mass is called glacier.