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.

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.

In computing, RAR is a proprietary file format for data compression and archiving, developed by Eugene Roshal (hence the name RAR: Roshal ARchive). The filename extension used by RAR is .rar. If a RAR-archive is broken into many smaller files (a multi-volume archive), as is often the case when it was distributed on Usenet, then those smaller files carry the extensions .rar, .r00, .r01, .r02 etc. and most unrar programs reconstruct the whole archive when provided with the .rar file.

File Extension PART could store file partially downloaded by browser. PART file contains only part of downloaded information and you need to complete the download in order to view information stored in it

A dynamic-link library (DLL) is a module that contain functions and data that can be used by another module (application or DLL). A DLL can define two kinds of functions: exported and internal. The exported functions are intended to be called by other modules, as well as from within the DLL where they are defined. Internal functions are typically intended to be called only from within the DLL where they are defined. Although a DLL can export data, its data is generally used only by its functions. However, there is nothing to prevent another module from reading or writing that address.

AAE extension is used to store and transfer information about adjustments to photo file on iOS 8 and later. Typically AAE file accompanies JPG file where actual photo is stored

CRDOWNLOAD is chrome partially downloaded file. Usually such file cannot be recovered since only part of it was downloaded. You need to visit website with download again and re-download it.

A file with the extension .dmg (an abbreviation for disk image) uses a disk image format commonly found on Mac OS X. The format allows secure password protection as well as file compression and hence serves both security and file distribution functions.

A dynamic-link library (DLL) is a module that contain functions and data that can be used by another module (application or DLL). A DLL can define two kinds of functions: exported and internal. The exported functions are intended to be called by other modules, as well as from within the DLL where they are defined. Internal functions are typically intended to be called only from within the DLL where they are defined. Although a DLL can export data, its data is generally used only by its functions. However, there is nothing to prevent another module from reading or writing that address.

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.

JNLP is short for Java Network Launching Protocol. This format is used by Java to download and launch applications over the network. JNLP applications typically don't run from user internet browser.

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.