Google is waking up to a new chief executive serving within a new corporate structure, one that makes the search engine business a subsidiary of a holding company called Alphabet. Co-founders, Larry Page and Sergey Brin, will now take on leadership of the parent company, leaving Google itself in the hands of 43-year-old Sundar Pichai.

Who is Pichai? And why was he chosen to lead Alphabet's most important division? Here's everything you need to know about the search giant's Indian-born leader.

You know how Google's the default search engine for many Web browsers? That was Pichai's work.

This probably doesn't sound like an exciting development, but making Google the default search engine in Internet Explorer and Firefox was critical in increasing Google's ubiquity. And, as Miguel Heft wrote in a 2014 piece on Pichai for Fortune, Pichai's dogged work on that product helped cement his reputation as a hard worker with the company's best interests in mind.

Pichai also helped make the case for Google's own Chrome browser when, in 2006, an update to Internet Explorer reportedly threatened to undercut Google's position in the browser field. The result was Chrome, a new platform where Google would never have to worry about playing second fiddle to anyone.

Together these moves helped extend Google's reach during a crucial period of growth. Without Pichai's efforts, Google probably wouldn't be as popular as it is today.

So is everything that happens on Android.

Since then, Pichai has gone on to manage other well-known Google applications, such as Gmail and Maps. But it's his most recent work overseeing Android that really put him on the tech world's radar. After taking over the unit in 2013, Pichai has rolled out three new versions of the mobile operating system, Jelly Bean, Kit Kat and the latest, Lollipop. Android accounts for 65 percent of the U.S. smartphone market alone. And at a developer conference this year, Pichai announced a slew of new operating systems aimed at everything from cars to thermostats.

"We are taking computing beyond mobile," he said at the time.

Now this "nice guy" will be overseeing even more.

Analysts seem to be welcoming Pichai's ascent to chief executive. He now seems to have intimate knowledge of seemingly every piece of Google. His affable, soft-spoken manner is a big contrast from some of the eccentric, hard-charging personalities that populate Silicon Valley. Here's what the founder of Giga Om, Om Malik, had to say on Twitter about Pichai when he got promoted to senior vice president of products last year:

"So @sundarpichai got a promotion to @google product czar. Congrats & proof nice guys can win. Though rapid reduction of odds of our dinner!"

That promotion has already given us a small glimpse into what Pichai's Google could look like — one that's very user-focused. During the keynote at this summer's Google I/O developers conference, Pichai focused heavily on Google's potential to connect consumers in emerging technology markets and provide every person on earth the opportunity to connect with smart devices.

"When we say 'be together, not the same,' that is precisely what we mean," Pichai said, in front of a world map of Android users. "We want to make sure we leave no one behind. We want to provide Android for users the way they like it, so that it works for them."

Pichai translates Larry Page for the company

With a refocused Google, many expect to see Pichai focus heavily on user-experience as the company strives to become the operating system for phones, smart devices, cars and everything else — a battle it will have to fight against Apple, Microsoft and Amazon.

Pichai is able to think both practically and conceptually — an asset within Google. Business Insider, citing anonymous sources at Google, reports that Pichai is known for being a "spokesman" and translator for Page, whose big thoughts don't always make sense in the context of running the company day-to-day. This could mean that we'll continue to see Page's influence on Google, if somewhat more subtly.

Page clearly thinks highly of Pichai, and his ability to think big and small. In the blog post announcing the Alphabet change, Page said, "Google itself is also making all sorts of new products, and I know Sundar will always be focused on innovation -- continuing to stretch boundaries. I know he deeply cares that we can continue to make big strides on our core mission to organize the world's information."

Pichai is now among the country's most powerful minority leaders.

Like Microsoft's chief executive Satya Nadella, Pichai is an Indian immigrant to the States. He studied metallurgical engineering at the Indian Institute of Technology Kharagpur. And he later earned graduate degrees in material science from Stanford University and in business from the University of Pennsylvania's Wharton School.

How did Pichai get started at Google?

Pichai did a stint at the consulting company McKinsey but according to the New York Times, he left for Google after "trying to talk one of his McKinsey colleagues out of going there, then realizing the arguments in favor of joining the company were better." He actually interviewed at Google on April 1, 2004 — the same day Google launched Gmail, according to Bloomberg.

If he's so great, how has nobody else tried to hire him?

Actually, Pichai's name was floated among tech insiders as a possible successor to former Microsoft chief executive Steve Ballmer, before that job ultimately went to Nadella. He has also been on some short lists for Twitter's chief executive position. With word of the promotion yesterday, even more kudos poured in -- including from his competitors Nadella and Apple chief executive Tim Cook, as well as from Indian prime minister Narendra Modi.