The most useful and practical use for the internet would be for communication. This comes in many forms today, it could be a text message, a meme you send your friend, or a post you make on social media, these are all forms of communication. The internet was revolutionizing communication in ways that were no feasible until its creating. I am talking about user generated content, this includes your Youtube videos, Facebook posts, and Reddit posts anything that comes from a person and not a big media company.
Before user generated content, big media companies controlled what they would present on their networks , but now it was all up to the individual. This scared big media companies, especially companies like YouTube. This was a new step in completely different direction where people could watch what they want, where they want, whenever they want, as long as it was on the site. No more waiting for America's Funniest Videos on TV, just go on youtube and search for funny videos. This was a great system, but it was not without its flaws, this system could be used for both good and bad even if it is not intented.
Music found its way onto the internet via Mp3. Mp3 is a file type which compresses audio into small files which can be easily shared across the internet. In comes Napster, which was a peer to peer software developed to share music from computer to computer. It's original intention was to only be used by a few people in a college, but it got leaked and was downloaded by millions. This resulted in the illegal sharing of copyrighted music online without permission of the creators and labels. This caused Napster to be shutdown in July of 2001. This shutdown paved the way for companies like Itunes to take the spotlight in online music sharing, where you have to pay in order to buy a certain track or album. It had become clear that the internet would become the number one source of sharing information and content, and would only grow larger in the future.