Adobe Reader is the default and official program that can open and display PDF files. Is not the single tool that is able to make it, but is designed by the company which has created PDF file format (Portable Document Application).
PDF files can contain text, images, links and does not depends directly by a computer program. Can be created by many freeware applications, share it or send it by email etc. and opened with different applications or PDF readers/viewers such as Adobe Reader.
This tool also offer basic editing features such as annotations and printing options.
