Foxconn, which is perhaps most known for assembling Apple's devices in its factories, has partially restarted operations in Shenzhen. The company closed its factories in the city a few days ago after the government imposed new lockdowns and restrictions in an effort to curb the country's worst COVID-19 outbreak in two years. According to Bloomberg, two of Foxconn's campuses in Shenzhen, one of which makes iPhones, won approval to partly restart their operations by adopting a "closed loop" management process.
Shenzhen is one of China's special economic zones and is known for serving as home to many electronics manufacturers. The tech hub has experienced tremendous economic growth over the past 10 years or so and contributes immensely — to the tune of hundreds of billions of dollars — to China's GDP. A long lockdown could lead to considerable economic loss for the country, which is most likely why Shenzhen said it would allow companies to operate, so long as they implement a "factory bubble" approach.
In this closed loop or factory bubble system, workers would have to live on site and can only travel from company housing to their workplaces. They also have to be tested regularly. Wuhan adopted similar measures when it went under a lockdown that lasted for months at the beginning of the pandemic. It's also similar to the bubble system used to protect athletes and locals during the Beijing Winter Olympics.
It's unclear if the factory shutdowns will have a huge effect on Apple's production rates, though it's worth noting that the tech giant has been grappling with supply chain issues and has been struggling to keep up with demand since last year.