remoteEval is to perform an action of some sort..
For instance...
remoteEval(2048, say, 0, "Woe is me!");
2048 is for client ID purposes.. If you are client-side scripting, it will always be 2048.
say is the command
0 is the parameter the command requires which I believe is text color (you can't change this from client).
Then after that is the rest of the command.
You could just as easily write say(0,"Woe is me!"); But from a server perspective, you can easily write remoteEval(%clientId, say, 0, "Woe is me!"); This will forward it to the client specified.
It is useful client-side for things you normally aren't able to do..
For instance...
remoteEval(2048, throwItem, 41, 1000); to throw a grenade at maximum force.
Next time, post this in assistance. It will get answered there faster than you think.