How To Use Events In Place Of For Loop

I have two questions:

1. I read somewhere that instead of looping through every player (below), you use could Events to do it for you:

for (Player player : this.getPlayers()) {
if (player.getLocation().getX() == 10) {
}
}

I'm not sure as to how to use Events in place of a for loop. I've been thinking on this for days, but I'm still stuck. Any example of using an Event instead of a for loop?

2. Is there any way to accept multiple connections on a server without using a while loop? Maybe use Events to handle the acceptance of connections?