Any downloadable file that contains more than simply human-readable, ASCII text. Typically, it refers to a program available for download, but it can also refer to pictures, sounds, or movies, among other things. Most newsgroups have subgroups specifically for binaries; a posting in comp.sys.mac.comm might announce that a program is available for download, but the binary (the file itself) would be found in comp.sys.mac.comm.binaries. Newsgroups, such as alt.pictures.binaries, contain files for download (in this case, pictures). You will need a newsreader to download and decode binary files.