[BullseyeHawk]

The first one is a quick formatted message, it's the same as:

pawn Код:

new string[128];
format(string, sizeof(string), "hello %d!", playerid);
SendClientMessage(playerid, -1, string);

The second one is a calculated distance, it creates a little equation that gives you the distance from points.
In the method you've showed us, it calculates the distance between a 2D space, OldCoordsX[i], x and OldCoordsY[i], y.