Glaciers are classified according to scale and location.
Another way is to consider the difference between 'WARM' (Temperate) and 'COLD' (Polar)
These can be identified using a temperature profile from the top of the glacier to the base.
Glaciers move due to the force of gravity.
Tend to form in high latitude locations: polar areas, particularly Antarctica
In areas of low relief
Where temperatures at the base are below the pressure melting point. This means that meltwater is not present beneath the glacier.
Where glaciers are stationary or move only very slowly.
They tend to protect the landscape.
Tend to form in lower latitude locations e.g French Alps
High altitude and steep relief. Necessary because there is less precipitation and warmer temperatures than those where polar glaciers form.
Basal temperatures are at or close to the pressure melting point, so that any additional pressure e.g an obstacle, may cause ice to melt.
Faster rates of movement (although many glaciers are in retreat)
Basal temperature is an important difference, and this controls the rate of movement.
Movement varies between, and within glaciers. Forbes' early experiments in the 1840's demonstrated that glaciers move fastest in the middle. The sides of the valley would obviously provide friction. Remember that glaciers are essentially layers of ice which have formed in annual layers of snowfall which has been compressed. The layers are shown by ogives: bands of summer and winter snowfall and dust.
Gradient affects the rate of movement, as one would expect.
There are 2 main types of moving:
BASAL SLIDING: a combination of factors relating to the presence of meltwater at the base
POLAR glaciers generally move by deforming internally.
Bear in mind that glaciers also move due to extending and compressing flow.