Word-based stream ciphers vs "regular" stream ciphers? Could somebody explain what is the difference between "word-based" stream ciphers and the regular ones? Those last ones use pseudo-random sequences XOR'd bit by bit with the message, as far as I know. How does that change when it comes to "word-based" ciphers?

Examples of word based keystream ciphers include SNOW, PANAMA, SOBER, ORYX. I also read that word based keystream ciphers "allow greater efficiency in software than most bit based stream-ciphers".
A word-based stream-cipher produces the pseudo-random sequence one word (of several bits) at a time. For example RC4 is a word-based stream cipher, with the word size a byte. By contrast, a typical bit-based stream cipher such as one using the ASG produces the pseudo-random sequence one bit at a time.

Word-based stream ciphers may be better suited to fast software implementations than are bit-based stream ciphers, since CPUs typically process one word no slower than one bit.