Mistwell
Crusty Old Meatwad
The only difference is in step #1. In previous editions (barring Spring Attack or the equivalent) you could move before you attacked, or after you attacked, but not both; if you started at a distance and closed to 10 feet away, you would have to end your turn there. In 5E, you can start at a distance, close, strike, and retreat again.
At a glance, this would seem to enable nasty hit-and-run tactics with a polearm, where you both start and end your turn outside your enemy's attack range. However, it turns out you have to have a very high movement rate to get any benefit from such tactics, and to avoid any retaliation at all requires a movement rate well into munchkin territory. When you think about it, 3E proved that the ability to split-move wasn't a problem. Otherwise every fighter would have picked up a polearm and Spring Attack.
Well, the polearm tactic still has some merit. If you have a front line fighter pinning the foes in one area at melee distance, and you run in and hit them with a polearm from the second rank and then run back, then the party is safer from area-attacks like fireball or a dragon's breath weapon. The less you clump together, usually the better...that is, until the invisible lurking predator hits the polearm guy that's separated himself from the pack.