Introduction

Apple File System is a new, modern file system for iOS, macOS, tvOS, and watchOS. It is optimized for Flash/SSD storage and features strong encryption, copy-on-write metadata, space sharing, cloning for files and directories, snapshots, fast directory sizing, atomic safe-save primitives, and improved file system fundamentals.

APFS replaces HFS+ as the default file system for iOS 10.3 and later, and macOS High Sierra and later.

Prerequisites

To understand how your app interacts with the file system, read File System Programming Guide.