Character Special Files
One of the examples of a special files are:
/dev/stdin/dev/stdout/dev/random(PRNG which may delay returning a value to acquire additional entropy.) That is why when Icat /dev/randomand do nothing else, it just prints the values, but when I start moving the mouse or turning on a movie - it’s hanging for a while./dev/urandom(PRNG which always returns a value immediately, regardless of required entropy.)
https://www.computerhope.com/jargon/s/special-file.htm#character-special
Hidden Markov Model - when a
References
[1] Silence on the wire, a Field Guide to Passice Reconnaissance and Indirect Attacks by Michal Zalewski
https://stackoverflow.com/questions/3080213/does-a-compiler-have-an-assembler-too