What does the term binary data mean?

Answer 1

Binary data means 0's and 1's. That is, information that can be transmitted across a network and is understood by a computer. It doesn't matter what the 0's and 1's actually represent -- that is a matter for the programs that use the data.

In point of fact, all data is binary. However plain-text (ASCII or UNICODE) is regarded as non-binary because it requires no special handling to translate the individual character codes back into a human-readable form. Video, image and sound files are all examples of binary data, because the data requires special handling to present the output in a form that humans can understand. Some binary data is never intended for humans, however. Executables, for instance, contain a mixture of binary data and plain text data, but the majority of that data is solely used by the computer itself -- machine code instructions to run the program. Portions of that code will translate into an interface that allow humans to interact with the program, producing yet more binary data that must be translated into a human-readable form, including plain text data.
All data is binary, however binary data refers to any non-plain text data, such as images, sound files, videos and executables, or proprietary data formats such as word processing files or any data that requires special handling to present the information to the user. Plain text files are binary as well, but the transition from binary to text requires no special handling because every ASCII/UNICODE character code translates directly to a symbol that is human-readable -- all you need is a text reader. Many binary files contain a mixture of binary data and plain text, but only the plain text portion is readable, everything else must be translated, usually by the program that created the file in the first place.

Answer 2

the binary number system is used to communicate in computers