In 2015 the US FCC took steps to prevent ISPs from discriminating against internet traffic. This is called Net Neutrality, which Wikipedia describes as “…the principle that Internet service providers and governments regulating the Internet should treat all data on the Internet the same, not discriminating or charging differentially by user, content, website, platform, application, type of attached equipment, or mode of communication.”
The gist of the concept is that the owner of the pipes shouldn’t be able to favour the delivery of its own content over content provided by others.
At the risk of oversimplifying this, net neutrality is generally favoured by consumers and content providers, but not so much by ISPs.
In what is seen as a backwards steps for US consumers, the new chair of the FCC has made it clear that he is not a fan of the principle.
For more detail, read this New York Times article titled Trump’s F.C.C. Pick Quickly Targets Net Neutrality Rules and this CNET article titled Meet the man who’ll dismantle net neutrality ‘with a smile’