The term means you take your initial workers and charge the enemy. If you know where the enemy is you'll arrive about the time they are up one or two workers on you, then you just have to fight when you're down one or two workers and you can't back off (they'll return to mine).
A human can win like this if they are so much better at micro that they can overcome the material disadvantage (unlikely) or if their opponent panicks and does something dumb (e.g. pulling only half their workers to fight).
Because worker rushes arrive so early it doesn't matter what plan you have for the match, you'll have at least as many workers (if you are also worker rushing) or you'll have more. Maybe if you're going six pool you'll have fewer but you'll also be able to get lings and win with them.
The computer can lose to worker rushing only because it can get caught in loops of poor decisions (e.g. you lure away a couple workers and kill them).
Worker rushing is always a bad plan.