The Internet, sometimes called simply "the Net," is a worldwide system of

computer networks -- a network of networks in which users at any one computer can, 

if they have permission, get information from any other computer 

(and sometimes talk directly to users at other computers).

How the Internet has changed the world?

The Internet has changed business, education, government, healthcare, and even the ways in which we interact with our loved ones—it has become one of the key drivers of social evolution. The changes in social communication are of particular significance.