Linear transformation and affine transformation are both concepts of transformation in mathematics, but there are some differences between them. Linear transformation refers to the transformation in vector space, which keeps the linear property in vector space unchanged. Simply put, it is to scale and rotate the vector without changing its direction. Affine transformation is a linear transformation from two-dimensional coordinates to two-dimensional coordinates, which keeps the "flatness" of two-dimensional graphics (straight line or straight line after transformation).

In other words, affine transformation includes linear transformation and translation transformation, which is naturally not equal to linear transformation. The translation time-base vector is unchanged, and the origin and the object move relatively, which is impossible to be realized by linear transformation. Therefore, the translation transformation is not a linear change. Affine transformation includes linear transformation and translation transformation.