yes true
it is a value derived from the steem power only
for example - you have 1000 teem power
at the moment of discussion the yearly intrest rate is 1.995%
then you will get 19.95 steem power yearly, but wait, it is added up on each second, so to make it easy you should calculate it daily for simple understandings
19.95 / 365 days = 0.05 steem power will be added into your steem power daily
and it is accumulating and compounding daily too