Network Neutrality

I have never heard “ network neutrality”, and I cannot understand the term well even though I search about it by using Internet. Network neutrality is “the principle that Internet users should be in control of what content they view and what applications they use on the Internet. The Internet has operated according to this neutrality principle since its earliest days”(http://www.google.com/help/netneutrality.html). Also, it says, “Net neutrality is a major issue as the U.S. considers new telecommunications laws. The U.S. House of Representatives passed its telecommunications bill, H.R. 5252, in May, without adequate net neutrality protections”. I am not sure, but it seems that the term has been debated in America for a long time, and recently, Japan has also started debating about it since 2006 according Internet. Now, there are both opinions that “net work neutrality” is good or bad.