Adding your dedicated servers to a pool allows you to manage your traffic consumption in every location more effectively.
Let's start from the very beginning – what is hosts file at all? I'm sure there is no need to tell you in details what Internet Protocol addresses are (IP-addresses or IP's for short) and why do we need Domain Name System (DNS). Information on this subject is easy to find and you have already heard something about it. Let's only highlight the main points.