Hello everyone.

I have one question… What means $FS…( I know $F and $FF.) I watched a Tut where they use in a Particle sim and I want to know the difference between the most common used $F and $FF and $FS
Thanks in advance.

not sure about $FS
but if you mean $SF then that stands for simulation frame, which is always 1 at the start frame of the simulation and increases by 1 every substep, so it has no relation to $F unless your sim starts at 1 and has 1 substep

$F is global timeline integer frame, so it'll return rounded integer value inbetween frames
$FF is global timeline float frame, so it'll return fractional frame numbers inbetween frames