Again, there were many vendors of many proprietary networks, but one, pushed by academic and military organizations, became the standard. This allowed email around the world. A higher level standard allowed the World Wide Web to be created, so software on any connected computer could display text and pictures from any web page. Computers don't have to be as interactive as people, so the information can take longer to get there. Computers can make big mistakes if even a single 0 is changed to a 1 by accident, so the information has to be verified.
Packet services are like mail.
Like mail, letters mailed in one order may not arrive in the same order. This is like not needing stamps on your letters. As you might expect, it makes overloads and junk e-mail common on the Internet. These differences between switched phone networks and packet computer networks will become important as we discuss their effect on videoconferencing. Early videoconferencing, which required huge amounts of data to be of any use, needed digital lines.