Chapter 2 Ajax introduction 1st brief introduction to Web Applications

Chaos is very simple at the beginning. To connect to a few of the top research institutions in the United States, the earliest "Internet" was designed for joint scientific research. Both librarians, nuclear physicists, and computer scientists must learn a rather complex system. 1962 j.c. r. when Licklider first proposed his "Galactic network" idea, convenient tools such as Firefox and IE were not even connected.

Licklider later continued his computer research at the US Defense Advanced Research Projects Agency (DARPA), where he actively promoted the importance of networked ideas. Almost at the same time, MIT's Leonard kleinrock and Lawrence G. Roberts are conducting research on group exchange theory, a core concept of computer networking. With the help of Thomas Merrill, Robert ts created the first Wan in 1965, connecting a TX-2 in Massachusetts to a Q-32 in California through a dial-up connection.

At the end of 1966, Robert ts came to DARPA with his experimental results, where he conceived a plan for the Advanced Research Projects administration network (ARPANET. At this point, kleinrock is at the network measurement Center of the University of California, Los Angeles, and is selected as the first node of ARPANET. It was here that BBN successfully installed the first group switch in 1969, called the interface message processors (IMP ). The Stanford Research Center was elected as the second node, where in October 1969, message exchange between the host and the host was implemented for the first time. Soon afterwards, the University of California Santa Barbara and the University of Utah were added as nodes, the predecessor of what we now call the internet.

In this period, minicomputers began to appear, Dec company launched a PDP-1, and subsequently launched a PDP-8, PDP-11 and VAX-11/780, and achieved great success. Computer capabilities have been greatly enhanced and increasingly convenient to use, unlike when there were only a few hosts at the beginning, people had to queue for use. Computers have become more common. However, the personal computer revolution has not yet arrived.

Initially, researchers believed that the TCP protocol was only applicable to large systems, because TCP was designed for large systems. However, the research team at the Massachusetts Institute of Technology David Clark found that workstations could also be interconnected with the mainframe. Clark's research, coupled with the explosive growth in the personal computer field in 1980s and 1990s, paved the way for the development of networks.

There were several major changes in 1980s. As the number of hosts grows from very few to thousands, You need to specify different names for the hosts so that people do not have to remember their digital addresses. This change, as well as the rapid growth in the number of hosts, gave birth to DNS. In addition, ARPANET switched from NCP to TCP/IP, which is a standard protocol used by the military. By the middle of 1980s, the Internet had been built into a platform connecting different groups of researchers, and other networks began to emerge: NASA created a span; the U. S. Department of Energy has established mfenet to study magnetic fusion energy, and csnet has been created with support from the National Science Foundation.

In 1989, Tim Berners-Lee from the European Institute of Particle Physics (CERN) proposed an interesting concept. He believes that, rather than simply referencing other people's books, it is better to carry out the actual link? When reading an article, the reader can open other articles referenced. Hypertext was quite popular at the time. Berners-Lee also used his previous research achievements in document and text processing to invent the Standard Generic Markup Language (SGML) is called Hypertext Markup Language (HTML ). The magic of HTML is that it can separate the information about the text display mode from the specific display implementation. Berners-Lee not only created a simple protocol called Hypertext Transfer Protocol (HTTP), but also invented the first web browser called worldwideweb.

From: http://book.csdn.net/bookfiles/11/10011433.shtml