Answer: Snow has many space for air into it buy glaciers do not contain any air gap and is compacted snow.
Explanation: Both Glacier and Snow are frozen form of water. Snow is the frozen form of precipitation which is differentiated from glaciers in terms of air and space inside it.
Snow crystals have lots of free form of crystal with lots of air inside it. Snow gets compacted to form glacier over a period of time.
Glaciers are the compacted form of snow which has been compressed over many years and has many layers of snow.