Alternate data streams

NTFS
Structures
Developer(s)	Microsoft
Full name	New Technology File System
Introduced	July 1993 with Windows NT 3.1
Partition identifier	`0x07` (MBR) `EBD0A0A2-B9E5-4433-87C0-68B6B72699C7` (GPT)
Directory contents	B+ tree
File allocation	Bitmap
Bad blocks	$BadClus (MFT Record)
Limits
Max. volume size	2⁶⁴clusters − 1 cluster (format); 256 TiB − 64 KiB (implementation)
Max. file size	16 EiB – 1 KiB (format); 16 TiB – 64 KiB (Windows 7, Windows Server 2008 R2 or earlier implementation) 256 TiB – 64 KiB (Windows 8, Windows Server 2012 implementation)
Max. number of files	4,294,967,295 (2³²-1)
Max. filename length	255 UTF-16 code units
Allowed characters in filenames	In Win32 namespace: any UTF-16 code unit (case-insensitive) except `/\:*"?<>\|` as well as NUL In POSIX namespace: any UTF-16 code unit (case-sensitive) except `/` as well as NUL
Features
Dates recorded	Creation, modification, POSIX change, access
Date range	1 January 1601 – 28 May 60056 (File times are 64-bit numbers counting 100-nanosecond intervals (ten million per second) since 1601, which is 58,000+ years)
Date resolution	100 ns
Forks	Yes (see § Alternate data streams (ADS) below)
Attributes	Read-only, hidden, system, archive, not content indexed, off-line, temporary, compressed
File system permissions	ACLs
Transparent compression	Per-file, LZ77 (Windows NT 3.51 onward)
Transparent encryption	Per-file, DESX (Windows 2000 onward), Triple DES (Windows XP onward), AES (Windows XP Service Pack 1, Windows Server 2003 onward)
Data deduplication	Yes (Windows Server 2012)
Other
Supported operating systems	Windows NT 3.1 and later Mac OS X 10.3 and later (read-only) Linux kernel version 2.2 and later ReactOS (read-only)

NTFS ("New Technology File System") is a proprietary file system developed by Microsoft. Starting with Windows NT 3.1, it is the default file system of Windows NT family.

NTFS has several technical improvements over the file systems that it superseded – File Allocation Table (FAT) and High Performance File System (HPFS) – such as improved support for metadata and advanced data structures to improve performance, reliability, and disk space use. Additional extensions are a more elaborate security system based on Access control lists (ACLs) and file system journaling.

macOS kernels also have a limited built-in ability to read NTFS (as well as limited write support, although by default it is not enabled). Linux and BSD kernels have a free and open-source driver for the NTFS filesystem with both read and write functionality.

In the mid-1980s, Microsoft and IBM formed a joint project to create the next generation of graphical operating system; the result was OS/2 and HPFS. Because Microsoft disagreed with IBM on many important issues they eventually separated: OS/2 remained an IBM project and Microsoft worked to develop Windows NT and NTFS.

The HPFS file system for OS/2 contained several important new features. When Microsoft created their new operating system, they borrowed many of these concepts for NTFS. NTFS developers include: Tom Miller, Gary Kimura, Brian Andrew and David Goebel.

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Wikipedia