According to rival Microsoft, Google owns the online search space and everyone else is playing in it.

This was the essence of Microsoft CEO Satya Nadella’s testimony in federal court on Monday during the government’s antitrust trial against Google. Google’s dominant market share in online search means publishers and advertisers shape their content to match Google’s requirements, making it difficult for competitors like Microsoft’s Bing to compete.

“Everyone talks about the open web, but the real web is the Google web,” Nadella said in Washington, D.C., District Court. Publishers often cater their content and advertising to Google’s products, such as optimizing their pages to rank higher in Google search results, according to Nadella.

Lawyers for the Department of Justice and a coalition of state attorneys general questioned Nadella about allegedly violating antitrust laws by maintaining a monopoly in the general search market. Through exclusive deals with browser and phone makers, Google locks up distribution channels for general search engines to become the default choice on different devices. One of the most famous deals is the multibillion-dollar agreement between Google and Apple to make Google search the default on Apple products.

In an attempt to defend its position, the government argues that Google’s dominance, aided by these exclusive deals, creates a flywheel effect, where more users lead to more data that makes Google’s search results better and attracts more advertisers. This, in turn, generates more revenue that can be used to fund these massive distribution deals.

The government argues that competitors lose out on the opportunity for greater benefits or innovations in search as a result of it becoming ever harder to penetrate consumers.

He described the obstacles a general search competitor like Bing faces to gain more market share from Google in his testimony on Monday.

Nadella’s testimony was not commented on by Google.