A random experiment, in which the event \(A\) can occur, is repeated \(n\ge 1\) times.
The absolute frequency (sometimes called cumulative frequency) of \(A\) is the number \(f_n(A)\) of times we observed the event \(A\) while the experiment was repeated \(n\ge 1\) times. Note that \(0\le f_n(A)\le n\).
The rational number \(F_n(A):=f_n(A)/n\) is called the relative frequency of \(A\).