Ever since it restructured into two companies, Google and Alphabet have had separate CEOs. Now that's changing and both entities will be under a single Chief Executive.

Google CEO Sundar Pichai is now CEO of both Google and Alphabet. Google co-founders Larry Page and Sergey Brin are stepping down from their roles as Alphabet CEO and President, respectively, but will remain active as co-founders, shareholders, and board members of Alphabet.

This change is effective immediately.

At the helm of Alphabet, Sundar Pichai will manage the company's investments in its Other Bets. He'll also continue to serve as a member of Alphabet's board of directors.

As for why this change is happening, Brin and Page say that Alphabet is now well-established after being created four years ago and that it and Google are effectively running as independent companies, and so they no longer need two separate CEOs. Today's change allows Google and Alphabet to simplify their management structure.

“I’m excited about Alphabet and its long term focus on tackling big challenges through technology," Pichai said. "I’m looking forward to continuing to work with Larry and Sergey in our new roles. Thanks to them, we have a timeless mission, enduring values, and a culture of collaboration and exploration. It’s a strong foundation on which we will continue to build."