footwork = putting your body in position to do the most damage to your opponent where your opponent can do the least damage to you. Anderson is the master of this.
movement = moving around the cage, cutting angles, staying active, to make your opponent not be able to anticipate your position ala Gustufsson, Cruz, Frankie ect.
Nick Diaz and Lombard both have great footwork, but terrible lateral movement.
Seriously, sometime watch Diaz or Lombard quickly scoot their front foot in a half-step motion toward their opponent when they are just out of range. The way they move their feet is very high level, which is why both land a very high percentage of punches standing. All the times Diaz has been put on his ass when from close range when he was in the pocket swinging where footwork holds no meaning.
Travis Browne has good movement, but unimpressive footwork.
Misses most of his punches, but when he does connect, its from on unexpected angle or position and puts the guy out.
The two are not interchangeable. Its just laughable reading SD talk about "footwork".
The worst footwork would be guys like: Beltran, Jardine, Leonard Garcia, Leben,, ect