Computer Network

The computer network is the facility to accommodate the user's computer in order to interact with each other. Through the network, users can exchange files, sharing (sharing resources) of a hardware device, and even control the other computer remotely.
Here are described some tissue samples, as follows:
Internet
Internet is not a network at all, but a large collection of different networks that use certain common protocols and provide certain public services.
ARPANET
ARPANET (Advanced Research Projects Agency Network) is a network of computers created by ARPA (Advanced Research Project Agency) of the U.S. Department of Defense in 1969. ARPANET functioned as a means of experimentation latest computer network technology of his day, such as packet switching technology and into the beginning of the establishment of the current Internet.
NSFNET
NSFNET is a network of the National Science Foundation Pemebrintah established by the United States in the late 1970s to the field of research and education. NSFNET also precisely what had once been the backbone Internet replaces ARPANET before being replaced by private commercial parties.
Use of the Internet
What exactly does it mean to be on the Internet? Our definition is that the machine is on the Internet if you are running TCP / IP protocol stack, has an IP address, and can send IP packets to all the other machines on the Internet. Ability only to send and receive electronic mail is not enough, because the e-mail address is gatewayed to many networks outside the Internet. However, this problem is somewhat blurred by the fact that millions of personal computers can call your Internet service provider using a modem, given a temporary IP address, and send IP packets to any other Internet host. It makes sense to think of the machine as it is on the internet as long as they are connected to the service provider router. Internet and its predecessors had four main applications:
E-mail. The ability to write, send, and receive electronic mail has been around since the early ARPANET and very popular. E-mail programs are available on almost all types of computers these days.
News. Newsgroups are specialized forums where users with common interests can exchange messages. Thousands of newsgroups exist, devoted to technical and non-technical topics, including computers, science, recreation, and politics. Each newsgroup has its own ethics, style, and customs, and woe betide those breaking them.
Remote login. Using telnet, rlogin, or ssh programs, users anywhere on the Internet can log on to another machine where they have an account.
File transfer. Using an FTP program, users can copy files from one machine to another on the Internet. A large number of articles, databases, and this.