The correct answer to this question is the Internet. The Internet is a part of our everyday lives. Whether for work, school, or to browse through Instagram, we all need the Internet. The first website was by Berners-Lee in 1991. This website was to teach users how to create theirs on websites.
Though the Internet is more used today, the concept has been around since the 1900s. Thinkers like Vannevar Bush and Paul Otlet knew that electrons could be used to communicate wirelessly. They did not have the technology available to make it happen. Another thinker and inventor, Tesla, is quoted as predicting smartphones.