A file extension created as the default file type created by Apple for their iWork product suite, which has included a spreadsheet program since its 2008 release. The .numbers file may contain the standard features of a spreadsheet file such as rows, columns, graphs, formulas and charts. The Numbers application also incorporates some of the functionality provided by the Lotus Improv application.
A .numbers file is actually comprised of a number of different files combined that together make up a .numbers file. Generally it will consist of a plist, a tiff image and an XML file. Similar to Microsoft products, the .numbers file type suffers from a lack of compatibility with other leading spreadsheet programs.
PDF is a file format developed by Adobe Systems for representing documents in a manner that is separate from the original operating system, application or hardware from where it was originally created. A PDF file can be any length, contain any number of fonts and images and is designed to enable the creation and transfer of printer-ready output.
Each PDF file encapsulates a complete description of a 2D document (and, with the advent of Acrobat 3D, embedded 3D documents) that includes the text, fonts, images and 2D vector graphics that compose the document. They do not encode information that is specific to the application software, hardware, or operating system used to create or view the document.