Tech giant Apple faces off with Epic Games, ‘Fortnite’ creators, in a trial that will determine how the App Store charges developers.

The trial began on Monday, and Apple CEO Tim Cook is expected to give evidence the first time he’s testifying at a trial.

The trial will conclude in the last week of May.

The tussle between both companies started last August, when Epic Games started in-app payments for its hit video game, Fortnite. This move bypassed Apple’s 30 per cent charges.

In retaliation, Apple removed Epic Games from the App Store.

Epic Games then instituted a 65-page lawsuit against Apple, likening the charges imposed on it to extortion.

The games company argued that Apple’s control over the App Store was anti-competitive and that developers should make apps for smartphones without having to pay huge sums.

Epic Games is not the first developer to complain about the rules around the App Store.

Companies like Netflix and Spotify have also complained about the arrangement.

Apple argued that it invented the App Store and could charge what it wants as a private company.

It also claimed that the 30 per cent charge to developers was the industry standard for gaming, and its payment system was fair to smaller developers.