The internet's availability is significant because it allowed all information to spread more easily and quickly than before. It also allowed for the spread of information that was only of interest to a small group of people even if thosepeople were spread around the globe.
For good or for bad, multiple people were now able to publicly (and possibly to a wide audience) their opinions and ideas. Instead of reading a book containing only the perspective of the author, you can now read the book and reponses to it, both positive and negative. While what happened in the past remains the same, presentation of this information can be biased so multiple perspectives is important.
Also, the way we view information is different. We can now easily see photos (professional and amateur) of events, hear sound recordings that were once only availabloccasionallythrough schools and libraries. The development of interactive websites allows us to feel more a part of events and discover content in the way that makes most sense to us.