right now, just now, At the moment
What is the difference between these words?
I mean, I can use them in any case
Right now- At this very moment, currently, as we speak. Just now- Literally just did, finished a second before you came up. At the moment- right now, currently, as we speak, what I am doing at this very second. The phrases "At the moment" and "right now" are synonymous. "Just now" is a very recent, just barely "past tense" (not exactly) phrase. Hope that helped.
They mean almost exactly the same thing. "Just now" probably refers to something that has already happened in the very recent past. "Right now" and "at the moment" likely refer to the present instant.