CSV file extension is used by files in comma separated values format. CSV files typically contain table information. First line of CSV file usually contains a table header and other lines contain table rows with data. Each line in CSV file consists of text strings delimited by commas. Each text string can contain any symbols except of the comma. If comma needs to be used inside the string, then string should be enclosed in quotes.

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.

The ZI extension represents the popular ZIP file, with a different name, to avoid mail and messaging server filters. Within the archive, there is at least one single file of any type.

GPX is the standard file extension for the exchange and storage of map and route data on GPS devices, smartphones and computers.

A file with DXF extension (acronym for Drawing Exchange Format) is a file format for CAD design drawings that belongs to the AutoCAD program group, and is used to save the drawings created by those programs. This type of files allows interoperability between the DWG files, proprietary file format of the AutoCAD program, and the rest of the programs on the market, proprietary or license free.

NUMBERS file extension is used to store files in Apple Numbers office application file format. Apple Numbers is a free application from Apple used to create and edit spreadsheets.

A file with an STP extension contains the 3D object project that meets the standards of the STEP format (Standard for exchanging product data). STP files are similar to STEP files in terms of structure and format, STEP is just less used.

KEY file extension is used to store files in Apple Numbers office application file format. Apple Numbers is a free application from Apple used to create and edit spreadsheets.