A ".nfo" file, sometimes referred to as a "readme" file, is a text-based document that is typically used to convey information about a downloaded package. Unlike an ordinary readme file, a ".nfo" file can sometimes contain elaborate ASCII art. The ".nfo" file extension is an abbreviation of the word "info."
This type of file is typically included with pirated software and media that is exchanged over file-sharing networks. The ".nfo" file often contains the crack or software serial number that allows the downloader to use the software as a legitimate purchaser, or it credits the person or group who recorded and packaged the included media. Files with this extension can ordinarily be opened using a text reader, such as Notepad; however, dedicated NFO viewing programs are also available.