Home > Metadata (computing)
Metadata is data about data. An example is a library catalog card, which contains data about the nature and location of a book: It is data about the data in the book referred to by the card.The content combined with its metadata is often called a content package.
1 Uses
Metadata has become important on the World Wide Web because of the need to find useful information from the mass of information available. Manually-created metadata adds value because it ensures consistency. If one webpage about a topic contains a word or phrase, then all webpages about that topic should contain that same word. It also ensures variety, so that if one topic has two names, each of these names will be used. For example, an article about sports utility vehicles would also be given the metadata keywords ‘4 wheel drives’, ‘4WDs’ and ‘four wheel drives’, as this is what they are known as in Australia, South Africa, and Namibia.
For an example of metadata for an audio CD, look at the MusicBrainz project, or the Musicbrainz Metadata Initiative. Similarly, MP3 files have metadata tags in a format called ID3.
Metadata is more properly called ontology or schema when it is of broad or narrow utility. Both terms describe “what exists” for some purpose or to enable some action. For instance, the library card’s minimal schema enables a user to determine quickly whether they wish to look at the book, and if so, how to find it quickly.
2 Filesystem metadata
Some file systems keep metadata about files out-of-band, while others keep it in the filename or inside the file. Examples of metadata are the filetype, abstracts, and iconA computer icon is a small graphic, usually ranging from 16 pixels by 16 pixels up to 128 pixels by 128 pixels, which represents a file, folder, application or device on a computer system. Icons were first developed as a tool for making computer interfaces. Examples of filesystems that keep metadata separate but related to the actual data are the BeFSThe Be File System (BFS, BeFS) is the native file system for the BeOS operating system. BFS was developed by Dominic Giampaolo and Cyril Meurillon in 1996 over a ten month period to provide BeOS with a modern 64-bit capable journaling file system. It is c of BeOSBeOS is a personal computer operating system developed by Be Incorporated in 1990 as a media OS. A highly modular OS written in completely new code (and not based on UNIX, a common misconception due to Be's inclusion of the Bash command shell and some sim, HPFSHPFS or High Performance File System is a file system created specifically for the OS/2 operating system to improve upon the limitations of the FAT file system. It was written by Gordon Letwin and others at Microsoft and added to OS/2 version 1. 2, at tha of OS/2OS/2 is an operating system created by Microsoft and IBM and later developed by IBM exclusively. The name stands for "Operating System/2", because it was intended as the preferred operating system for IBM's " Personal System/2 ( PS/2)" line of second-gene, HFSHierarchical File System HFS , is a file system developed by Apple Computer for use on computers running Mac OS. Originally designed for use on floppy and hard disks, it can also be found on read-only media such as CD-ROMs. History HFS was introduced in J/ HFS PlusHFS Plus or HFS is a file system developed by Apple Computer to replace their Hierarchical File System (HFS) as the primary file system used on Macintosh computers. It is also one of the formats used by the iPod hard-disk based music player. HFS Plus was of Mac OS, ReiserFS of Linux, and NTFS of Windows.
The next major releases of Mac OS X ( Tiger) and Windows ( Longhorn) were expected to include new features that would allow greater flexibility in the maintenance and searching of metadata. Apple has announced that it plans to release Tiger with its Spotlight technology in the "first half of 2005", however on August 27 2004 Microsoft announced that when the client and server versions of Longhorn ship in 2006 and 2007, its new filesystem WinFS will only be available as a beta product.
