facets of what i deem important knowledge on this topic
multiple separate sound channels like stereo channels are typically stored in one of two ways:
two pi radians are one full sine cycle. one hertz is one full cycle per second. one hertz equals sampling-rate number of samples. the maximum representable frequency in hertz is (sampling-rate / 2), an integer if sampling-rate is even.
sample count is an exact integer measure for a progressing time value, durations or signal widths for example.
the use of seconds can be problematic because the length of one sample might be represented with inexact numbers. for example
1 / 44100 = 0.000022675736961451248 and
1 / 48000 = 0.000020833333333333333
seconds do not depend on the sampling rate.