XLS is a proprietary binary file format called Binary Interchange File Format (BIFF) as its primary format used by Excel to store spreadsheet information. Excel 2007 uses Office Open XML as its primary file format, an XML-based container similar in design to XML-based format called XML Spreadsheet (XMLSS), first introduced in Excel 2002.

Temporary files may be created by computer programs for a variety of purposes; principally when a program cannot allocate enough memory for its tasks, when the program is working on data bigger than architecture's address space, or as a primitive form of inter-process communication.

MPEG-4 Part 14, formally ISO/IEC 14496-14:2003, is a multimedia container format standard specified as a part of MPEG-4. It is most commonly used to store digital audio and digital video streams, especially those defined by MPEG, but can also be used to store other data such as subtitles and still images. Like most modern container formats, MPEG-4 Part 14 allows streaming over the Internet. The official filename extension for MPEG-4 Part 14 files is .mp4, thus the container format is often referred to simply as MP4.

BUP (Back UP) is the filename extension of some files stored on video DVDs. The BUP file is a backup of the IFO file on a DVD, which contains the information about the organization of tracks, menus, chapters, subtitles on the disc. The BUP files are used in the event that the corresponding IFO file is unreadable, perhaps due to a scratch on the surface of the disc.

Small, icon-sized image used to represent a larger image; commonly used on the Web or in clip art galleries; may be created by various photo or video editing programs; also produced by some digital cameras as small sample images of photos saved on the camera.

Microsoft PowerPoint (file extension PPT) is a presentation program developed by Microsoft. It is part of the Microsoft Office system. Microsoft PowerPoint runs on Microsoft Windows and the Mac OS computer operating systems. It is widely used by business people, educators, students, and trainers and is among the most prevalent forms of persuasion technology. Beginning with Microsoft Office 2003, Microsoft revised branding to emphasize PowerPoint's identity as a component within the office suite. Microsoft began calling it Microsoft Office PowerPoint instead of merely Microsoft PowerPoint. The current version is Microsoft Office PowerPoint 2007. As a part of the Microsoft Office suite, PowerPoint has become the world's most widely used presentation program.

File extension BAK is given to files used for backup of another document, often created automatically by various programs or the operating system; for example, Windows may create BAK files for the System.ini and Win.ini files.

File extension OFX stands for Open Financial Exchange file. It is used by financial application to exchange information between various sources.

The Portable Document Format (PDF) is the file format created by Adobe Systems in 1993 for document exchange. PDF is a fixed-layout format used for representing two-dimensional documents in a manner independent of the application software, hardware, and operating system. Each PDF file encapsulates a complete description of a 2-D document (and, with Acrobat 3-D, embedded 3-D documents) that includes the text, fonts, images, and 2-D vector graphics that compose the documents.

DAT file extension could represent following file types:

- Data file

- A data file extension used to designate an error message in a inbound internet email message (Microsoft Exchange Server v 5.0)

- WordPerfect Merge Data

- Extension used for some MPEG files

- Yahoo Messenger archive file

The .BIN/.CUE image file format was developed by Jeff Arnold for the CDRWIN program. An image consists of two files which contain binary data and metadata, respectively. The filenames typically match (e.g. image.bin and image.cue). The .BIN file contains an exact copy of all data stored on an optical disc in raw, unprocessed form but without any subchannel data. For this reason, some programs use the .RAW suffix for these files.