In computing, DLL (an abbreviation of 'Dynamic Linked Library') is a file extension for executable libraries. DLL files are commonly used by software programs to store parts of the executable code.

BIN file is short for binary file. It is impossible to open BIN files in text editor because they consist of information in binary form which could only be enterpreted by computer applications or operating system. This extension is also associated with extension used for UNIX executable files.

Direct Access Archive, or DMG, is a proprietary file format developed by PowerISO Computing for disk image files which supports features such as compression, password protection, and splitting to multiple volumes. It can be handled like a file just like other formats, such as an ISO image and BIN, but is currently only usable by PowerISO software. Popular disk image mounting programs such as Alcohol 120% and Daemon Tools currently do not support the mounting of DAA images.

APK extension is used to deliver and install application software and middleware onto Google Android system. APK file contains compiled Android application code and all resources which are required by this code.

You can open XLS file using Microsoft Excel application. Microsoft Excel is similar to other spread sheet applications that can store information that can be edited and viewed on several platforms. You can run Microsoft Excel and open XLS files on Mac and Windows through installed Microsoft Office applications.

HEIC is a new file format designed to store highly compressed photos and videos. HEIC and HEIF formats were developed by MPEG group and are currently adopted by multiple vendors including Apple and Microsoft.

PDF is short for "Portable Document Format" which was created by Adobe Systems in 1993 to facilitate document exchange. After creation of the internet this format experienced significant growth and became de-facto standard for document exchange on the internet.

TMP files are used to store temporary information. Typically these files are stored only while information in them is needed by an application or operating system and are deleted as soon as this information becomes obsolete.