Net Neutrality rules prevent internet service providers from favoring or blocking certain websites. It also prevents them from charging you extra based on the content of a website.
Without Net Neutrality, an internet service provider could sell service that blocked or filtered out websites with views that it disagreed with. Repealing the rules would also allow internet service providers to charge you extra to get access to the websites you like the most. Want Netflix? Pay an extra $5.
We already have extra charges in everything from airplane flights (extra for food, legroom, or checked baggage) to video games (pay to win). This could do the same for the Internet.
Most importantly, it would allow internet service providers (big corporations) to disfavor websites that they disagree with. The value of the internet is that it is a free zone of information where people who disagree with each other interact. We don't have enough of that.
We are fractured enough, and it's already hard for under-funded views to get their message out. In an age where big media mergers threaten a diversity of views, we need to save Net Neutrality so we can save a free and open internet.