Frequently encountered binary files include:
1. Files that use proprietary formats, such as word-processing programs, spreadsheets, database programs, etc. These files contain formatting (like italics, underlines, etc.) and perhaps graphics, and other goodies beyond the simple text.
2. "Application Programs". These are programs written in (the binary) machine language that your computer understands. They are "compiled" from text files of "source code" written in a programming language. Vendors almost never make their source code available—except for free software, which you may have to compile yourself.
3. Text files that have been compressed to about half their size with one of the popular compression programs. Compression makes texts files binary. Compression doesn't do much for files that are already binary unless the data they contain is very repetitive.
4. Files containing graphics like GIF, TIFF, PICT, or JPEG files.
More on this below.
Transfering binary files is as easy as transfering text files once you understand the potential problems:
1. Most FTP programs start you out in TEXT mode. This means that text files are *translated* when they go from computer to computer on their way to you. This is fatal to binary files because their bit pattern has nothing to do with the groups of eight bits that make up text.
2. Even text files have slight compatibility problems because the three "worlds"—IBM, Macintosh, and UNIX—use a different control character to represent "return", "enter", or "newline." Translation between the different dialects is handled automatically in TEXT mode transfers. It is also the main reason why text files cannot be transfered in BINARY mode.
The two control characters involved are called "linefeed" (LF) and "carriage return" (CR):
IBM PC and compatibles : <LF> <CR>