look up round-robin DNS online. It is a cheap method for load balancing.
For example, you got 2 IP addresses for website "test.com". When you try to access it, it will return IP1, and when I try to access it, it will return IP2.
There are some interesting information in this post also. Feel free to take a look, maybe you'll find it useful:
Hopefully I cleared it out a bit for you.