Ten years ago this September, two Stanford University doctoral students launched a business that would revolutionize how millions of people use the Internet.

Yes, Google is getting older, at least in tech years.

But don't expect the world's dominant search engine company to remain content with the enormous success it has achieved so far.

Google is rolling out innovative features that will allow users to search the Web more efficiently. It is also looking to expand its advertising reach, focusing on the folks who do their queries via mobile phones
and car-based systems. Google has been increasing its spending on research and development, which totaled $2.1 billion last year alone.

The company has come a long way since Sergey Brin and Larry Page started Google in a garage in Menlo Park, Calif. One of the most feared and respected technology giants in the world, Google earned $4.2 billion in profits last year and employs nearly 17,000 workers.

With more than half of its user traffic coming from outside the United States, Google has evolved into a global company. It operates 60 offices in 20 countries.

Google regularly makes improvements to its search engine, which now contains billions of Web pages compared with only 30 million in 1998.

However, it took a major leap last year by introducing what it calls ''universal search.'' This is a more comprehensive search engine that includes video, images, maps, news and other data. Previously, you had to visit several Google search products to get different types of information.

Marissa Mayer, Google's vice president of search products and user experience, described universal search as a large step forward because it involved installing a new technical infrastructure.

The search engine's next frontier lies in blending in new media and adapting to the different technologies that people are using to make search queries, such as mobile phones and car-based systems.

With competition expected to intensify, what will differentiate Google from others? Mayer cites three factors: comprehensiveness, relevance and the user experience.

Google plans to offer more content than anyone else, not just Web pages but also books, video, news and images, she said.

In the future, people may be able to express their search queries in far different ways than is possible today.

''We're constantly looking at user intent,'' Mayer said.

Google may operate the world's most popular search engine, but it still makes money the old fashioned way: from advertisers. Last year, advertisers generated 99 percent of the company's $16.6 billion in revenues.

Most of this money comes from AdWords, the four-line text ads that companies create. Advertisers bid against each other to have their ads pop up to the right of or on top of Google's search engine results whenever Internet users type in certain words that the companies select in advance.

Once an ad is triggered, what determines whether it gets the top spot on the page? An advertiser's bid and the ad's quality score, a judgment by Google about how likely Internet users are to find the ad relevant.

Google won't reveal how it derives its quality scores. The rankings are important to Google because it only makes money if Internet users click on the ads.

Richard Holden, product management director for AdWords, said that Google has found that AdWords works best with advertisers looking to generate a direct response, such as buying a product or signing up for an e-mail list. This kind of advertising is different from trying to build a brand.

Google's ambitions stretch far beyond AdWords.

The company wants to bring its ability to measure the effectiveness of ads to other forms of advertising such as radio, television and print.

Google's recent acquisition of DoubleClick Inc., a New York-based provider of digital marketing technology and services, should help it extend its reach into traditional advertising, Holden said.

Google recently began selling TV commercials in North America. It has already signed up 3,000 national advertisers. So far, the commercials only run on the Dish satellite network.