What is the mean of M & G in silicon wafer dimensions?

The difference between M and G is the shape of photovoltaic silicon wafer.

G starts with a square piece.

M starts with the chamfered piece, that is, the square piece cuts off four corners.

For example, M10 chamfered piece with side length of 182mm. If you use a 10 inch diameter silicon rod to cut the square, there is no loss at the limit, it can only be about 179.6mm. A piece that cuts a square from a circle.