(APple File System) The latest file system for Apple products, introduced in 2017. APFS, which is the software that reads data from and writes data to storage, became part of the following operating systems: macOS High Sierra, iOS 10.3, tvOS 10.2 and watchOS 3.2. Optimized for solid state drives (SSDs), APFS supports most of the features in the previous HFS+ file system, which Macs still support (see HFS).APFS provides more crash protection than HFS+ (see copy-on-write), and it supports one nanosecond timestamps, compared to one second previously. It also saves storage space (see sparse file). With native encryption support, APFS combines features from iOS and OS X. APFS-formatted volumes are not supported in OS X Version 11.11 and earlier but can be shared via the SMB file sharing protocol (see SMB). See High Sierra and file system.