APFS

Apple File System
Limits
Developer(s)	Apple Inc.
Full name	Apple File System
Introduced	March 27, 2017 with iOS 10.3
Max. file size	8 EiB
Max. number of files	2⁶³
Features
Date resolution	Nanosecond
Transparent encryption	Yes
Copy-on-write	Yes
Other
Supported operating systems	macOS, iOS, tvOS, and watchOS

Apple File System (APFS) is a file system for macOS, iOS, tvOS and watchOS that is being developed and deployed by Apple Inc. It aims to address the core issues of the existing HFS+ (also called Mac OS Extended) file system in use on these platforms today. Apple File System is optimized for flash and solid-state drive storage, with a primary focus on encryption.

Apple File System was announced at Apple's developers conference (WWDC) in June 2016, replacing HFS+ that has been in use since 1998, in an era of floppy disks and hard drives. It was released for iOS devices on March 27, 2017, with the release of iOS 10.3.

The file system scales from an Apple Watch to a Mac Pro. It uses 64-bit inode numbers, and allows for more secure storage. The APFS code, like the HFS+ code, uses the TRIM command, for better space management and performance. It may increase read-write speeds on iOS and macOS, as well as space on iOS devices, due to the way APFS calculates available data.

Clones allow the operating system to make fast, power-efficient file copies on the same volume without occupying additional storage space. Modifications to the data write the new data elsewhere and continue to share the unmodified blocks. Changes to a file are saved as differences of the cloned file, reducing storage space required for document revisions and copies.

Apple File System supports snapshots for creating a point-in-time, read-only instance of the file system.

Apple File System natively supports full disk encryption, and file encryption with the following options:

...
Wikipedia