A 4x4 matrix can represent a position and a rotation, where the 3x3 matrix (called the transform) is the rotation and the 4th row (calls the transpose) is the l

A 4x4 matrix can represent a position and a rotation, where the 3x3 matrix (called the transform) is the rotation and the 4th row (calls the transpose) is the location in space. The neat thing is that when you multiply matrices together you update the original matrix. e.g. If you want to rotate something 90degrees to the right, you make a transform matrix with a zero transpose and multiply it with the original matrix. The resulting matrix will be an object in the same place rotated by 90 degrees. Most modeling applications since about 2000 though use quaternions and a point to represent rotation and location. That's because it uses less memory and is easier/faster to compute.