John Ternus has officially taken over as Apple's CEO, succeeding Tim Cook who has transitioned to executive chairman. Ternus, who has been with Apple since 2001 and previously led hardware engineering, is 51 years old and expected to lead for a significant period. Tim Cook will now focus on assisting with specific company initiatives and engaging with global policymakers. Cook concluded his tenure as CEO with a visit to the Apple Park Visitor Center to connect with retail employees.