John Ternus takes the helm at Apple, ending Tim Cook's 15-year tenure

Apple's new CEO John Ternus takes the helm of the iconic tech giant on Tuesday, ending Tim Cook's 15-year tenure. Cook will remain with the company as executive chairman, where he is expected to help maintain relationships with figures such as President Donald Trump, who offered public praise for him on Tuesday.

Ternus steps into the role during a pivotal period for the company. Apple has struggled to deliver on artificial intelligence features it promised nearly two years ago, though earlier this year it unveiled new AI initiatives, including upgrades to its Siri assistant, with an emphasis on privacy and day-to-day use.

Ternus, who worked on signature Apple products including the iPhone, will also need to navigate supply chain questions. Cook cultivated ties with Trump while steering the company through challenges including the former president's trade and tariff war targeting countries in Asia, where Apple has extensive manufacturing operations.

Cook's tenure saw Apple's market value grow to roughly $4.6 trillion. He took over as CEO in 2011 from Steve Jobs, who stepped down due to health concerns and died two months later.