Net Neutrality

At its core, net neutrality determines whether Internet Service Providers (the companies that own the cables all internet traffic runs on) can charge more for certain kinds of traffic or not. For example, AT&T or Comcast might charge Netflix (or its consumers) more for Netflix traffic than they charge Wikimedia (or its consumers) for Wikipedia traffic —a site streaming video requires more bandwidth than a text-based site. 

ISPs want to charge different rates for different types of content. This would allow them more profits that they might choose to invest in infrastructure improvements. The technology sector depends on predictably inexpensive internet traffic in order to innovate and disrupt. And the technology sector would argue that if the ISPs can determine price, then they could have blocked a service Netflix in the very beginning and hence never had to face the competition from Netflix. 

Currently ISPs are not allowed to charge different rates for different types of content. This is something Obama has fought for. Trump on the other hand does not like Net Neutrality (Recode).

From perspective of a society what should concern all of us is what we value. On one hand you could, as the technology sector would encourage you to, look at internet as infrastructure such as roads, electricity, and water, and hence consider AT&T, Comcast, and others as semi-public goods that should be open to all to innovate on. On the other hand, the ISPs would ask you to consider that they are indeed private companies and not public sector and should be able to make money on their investments and only if they can charge differently are they incentivized to expand their services. See more about the history of net neutrality here. (Whitehouse.gov

Timeline