What is the difference between inversion and fronting?

What is the difference between inversion and fronting?

Inversion is often taken to be similar to fronting, with the mistaken idea that they both move an item to the front position. Their difference is twofold: first, inversion involves the reversal of subject verb order while fronting usually does not; in the second place, whereas fronting usually transfers the information focus from the final position to the front, inversion may comply with either fronting or postponement depending on its structure.