Though just 25 years old, the World Wide Web's short life can be understood in stages. It's often used synonymously as the Internet. But the Internet is the network connecting computers globally. The Web is built on top of it, a way to access and share information (think Web pages) over the Internet.

Here are the key elements of the World Wide Web's life so far:

BIRTH: On March 12, 1989, Tim Berners-Lee wrote a paper for his employer for a way to keep and access documents even after employees leave. His boss at the European Organization for Nuclear Research (CERN) in Geneva, Switzerland, described the idea as "vague but exciting."

FIRST STEPS: Berners-Lee began to implement the idea and named the project the "World Wide Web" (other names considered were Information Mesh, Mine of Information, and Information Mine). Using a NeXT computer, he created the code and first standards for the Web and published the first website.

In a 2007 interview, Berners-Lee said: "Most of the technology involved in the Web...had all been designed already. I just had to put them together."

BROWSER YEARS: Mosaic wasn't the first Web browser, but it was widely downloaded after it launched in 1993 and was considered the first to make the Internet accessible.The following year, Mosaic's competitor, Netscape Navigator was released.

In the same year, Yahoo, which made the Internet more accessible and usable, is founded.

COMMERCIAL WEB: These were the years of the dot-com boom with the rise of the commercial Web. In 1995, eBay, known then as Echo Bay, launched, as did Amazon. HotMail came along the following year. And then, in 1998, Google was born. But many other dot-com companies died during the bust in 2000 when the Nasdaq lost 10 percent of its value in a single day. They include Webvan and Pets.com.

SOCIAL WEB: First there was MySpace, which launched in 2003 and quickly became popular. In 2004, Facebook was hatched, but opened at first only for college students. YouTube allowed people everywhere to watch and upload videos, but it rattled Hollywood. Twitter, born in 2006, gave people a new platform to broadcast their thoughts to a wide audience.

THE MOBILE REVOLUTION: With the 2007 unveiling of Apple's iPhone, the advent of the mobile Web begins, as people use mobile networks to access apps, messaging and other uses.