List of file formats
This is a list of file formats used by computers, organized by type. Filename extension it is usually noted in parentheses if they differ from the file format name or abbreviation. Many operating systems do not limit filenames to one extension shorter than 4 characters, as was common with some operating systems that supported the File Allocation Table (FAT) file system. Examples of operating systems that do not impose this limit include Unix-like systems, and Microsoft Windows NT, 95-98, and ME which have no three character limit on extensions for 32-bit or 64 -bit applications on file systems other than pre-Windows 95 and Windows NT 3.5 versions of the FAT file system. Some filenames are given extensions longer than three characters. While MS-DOS and NT always treat the suffix after the last period in a file's name as its extension, in UNIX-like systems, the final period does not necessarily mean that the text after the last period is the file's extension. Some file formats, such as codice_1 or codice_2, may be listed multiple times. (MPEG-1 is found in a .DAT file on a video CD.) Computer-aided design . Computer-aided is a prefix for several categories of tools (e.g., design, manufacture, engineering) which assist professionals in their respective fields (e.g., machining, architecture, schematics). Computer-aided design (CAD). Computer-aided design (CAD) software assists engineers, architects and other design professionals in project design. Electronic design automation (EDA). Electronic design automation (EDA), or electronic computer-aided design (ECAD), is specific to the field of electrical engineering. Test technology. Files output from Automatic Test Equipment or post-processed from such. Document. These files store formatted text and plain text. Graphics. Raster graphics. Raster or bitmap files store images as a group  of pixels. Vector graphics. Vector graphics use geometric primitives such as points, lines, curves, and polygons to represent images. 3D graphics. 3D graphics are 3D models that allow building models in real-time or non-real-time 3D rendering. Reference management software. Formats of files used for bibliographic information (citation) management. Security. Authentication and general encryption formats are listed here. Encrypted files. This section shows file formats for encrypted general data, rather than a specific program's data. Password files. Password files (sometimes called keychain files) contain lists of other passwords, usually encrypted. Video game data. List of common file  formats of data for video games on systems that support filesystems, most commonly PC games. Video game storage media. List of the most common filename extensions used when a game's ROM image or storage medium is copied from an original read-only memory (ROM) device to an external memory such as hard disk for back up purposes or for making the game playable with an emulator. In the case of cartridge-based software, if the platform specific extension is not used then filename extensions ".rom" or ".bin" are usually used to clarify that the file contains a copy of  a content of a ROM. ROM, disk or tape images usually do not consist of one file or ROM, rather an entire file or ROM structure contained within one file on the backup medium. Generalized files. General data formats. These file formats are fairly well defined by long-term use or a general standard, but the content of each file is often highly specific to particular software or has been extended by further standards for specific uses. Generic file extensions. These are filename extensions and broad types reused frequently with differing formats or no specific format by different programs. List