# Apple Disk Image

> disk image file format developed by Apple and commonly used by macOS

**Wikidata**: [Q1228757](https://www.wikidata.org/wiki/Q1228757)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Apple_Disk_Image)  
**Source**: https://4ort.xyz/entity/apple-disk-image

## Summary
Apple Disk Image (ADI) is a disk image file format developed by Apple Inc. and commonly used by macOS. It allows users to store the contents and structure of a disk volume in a single file, making it easy to distribute, archive, or transfer data.

## Key Facts
- Developed by Apple Inc., a multinational technology company founded in 1976.
- Primarily used for digital preservation and storing disk volume contents in a single file.
- Common file extensions include `.dmg`, `.smi`, `.img`, and `.image`.
- Media type: `application/x-apple-diskimage`.
- Supports formats like Sparsebundle and Sparseimage.
- Used in macOS for distributing software and data.
- Recognized by PRONOM as file format ID `fmt/625`.
- Identified by the hexadecimal pattern `7801730D626260`.

## FAQs
### Q: What is an Apple Disk Image used for?
A: Apple Disk Image is used to store the contents and structure of a disk volume in a single file, making it easy to distribute, archive, or transfer data, particularly in macOS.

### Q: What file extensions are associated with Apple Disk Image?
A: Common file extensions include `.dmg`, `.smi`, `.img`, and `.image`.

### Q: Who developed Apple Disk Image?
A: Apple Disk Image was developed by Apple Inc., a multinational technology company founded in 1976.

### Q: How is Apple Disk Image used in digital preservation?
A: Apple Disk Image is used in digital preservation to ensure that digital information remains accessible, trustworthy, and usable by storing disk contents in a single file format.

### Q: What is the media type for Apple Disk Image?
A: The media type for Apple Disk Image is `application/x-apple-diskimage`.

## Why It Matters
Apple Disk Image plays a crucial role in macOS by providing a standardized way to distribute and store disk contents. It simplifies the process of transferring data, archiving files, and installing software, making it an essential tool for users and developers. Its use in digital preservation ensures that important data remains accessible and intact over time. The format's compatibility with macOS and its ability to handle large volumes of data make it a valuable asset in both personal and professional computing environments.

## Notable For
- One of the most widely used disk image formats in macOS.
- Supports multiple file extensions, including `.dmg` and `.smi`.
- Recognized by PRONOM for its standardized file format identification.
- Used in digital preservation efforts to maintain data integrity.
- Identified by a unique hexadecimal pattern for file format recognition.

## Body
### Overview
Apple Disk Image (ADI) is a disk image file format developed by Apple Inc. It is designed to store the contents and structure of a disk volume in a single file, making it easier to distribute, archive, or transfer data. The format is commonly used in macOS for various purposes, including software distribution and data backup.

### Development and Usage
Apple Disk Image was developed by Apple Inc., a company known for its innovative technology and software solutions. The format is primarily used for digital preservation, ensuring that digital information remains accessible and trustworthy. It supports multiple file extensions, including `.dmg`, `.smi`, `.img`, and `.image`, each serving different purposes within the macOS ecosystem.

### Technical Details
The media type for Apple Disk Image is `application/x-apple-diskimage`, and it is recognized by PRONOM as file format ID `fmt/625`. The format is identified by the hexadecimal pattern `7801730D626260`, which helps in its recognition and validation. Additionally, Apple Disk Image supports formats like Sparsebundle and Sparseimage, which are used for efficient storage and management of disk images.

### Significance
Apple Disk Image is notable for its widespread use in macOS, where it serves as a standard for distributing and storing disk contents. Its role in digital preservation ensures that important data remains intact and accessible over time. The format's compatibility with macOS and its ability to handle large volumes of data make it a valuable tool for users and developers alike.

## References

1. Freebase Data Dumps. 2013
2. [Source](https://www.nationalarchives.gov.uk/PRONOM/Format/proFormatSearch.aspx?status=detailReport&id=1424&strPageToDisplay=signatures)
3. Gary Kessler's File Signature Table