Along with the speed, APFS supports far more files than ever, letting you put nine quintillion of them on a single volume. Security-wise, it includes multikey encryption, making it tough for bad guys (or law enforcement and spies) to crack even if they have physical access to your drive. That encryption will also work in a unified way across all of Apple's devices. At the same time, APFS is backwardly compatible with all of your HFS formatted drives.
Apple File is arguably a more important update on macOS than other devices, because a lot of creative folks lean on their Macs for disk-heavy tasks like video and photo editing. As Apple VP Craig Federighi showed on the stage, copying files now runs nearly instantly on Apple File, compared to the now-decades-old HFS filesystem. It offers not only better throughput but also faster latency -- important if you're handling lots of files.
Apple says that the new advanced file system is "optimized for modern storage," including fast SSDs and flash, Lightning and USB drives. It will also easily adapt to future types of storage, the company says. The new file system will arrive sometime in September at Apple's usual iPhone event with the launch of macOS High Sierra.
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