pdf The .pdf file format extension was developed by Adobe systems in 1993 as a means of presenting documents in a consistent manner across different platforms, hardware, operating systems, and applications. The format was not released as an open source document format until 2008, though minimal proprietary technologies still controlled by Adobe Systems exist in the format. Every .pdf document carries with it the necessary meta information required to properly reconstruct the text, fonts, and graphics used to produce the document. This ensures that documents will be viewed in exactly the same way the author intended regardless of the device used to open the document. From conception to date, Adobe Systems has continued to support the format adding features with every iteration of the standard including hardened algorithms for document encryption and privacy. Today, many freely available readers exist allowing you to open and view .pdf documents and create or convert other file formats such as .jpeg and .doc into .pdf documents.
zip The .ZIP file extension format is a file archive and data compression format originally developed and released in 1989 by Phil Katz. With compatible zip format software, a file or a group of files can be packed (compressed) into a single .zip archive which can later be unpacked (decompressed). The zip file archive format facilitates the distribution of multiple files as single archives particularly over the internet and networked systems. Many operating systems have native support for the file format and can usually open zip archives without the need for third party software. Microsoft windows for instance has had native support for the ZIP format since Microsoft Windows 98, similarly Apple's Mac OS includes ZIP support through its default archive file handle Archive Utility.