The symbol Histogram is used as a key in the hash table returned by the function statistics. It one of the summary statistics for a given data sample.
i1 : s=sample(ER(6,3,0.2),100);
i2 : myStats = statistics(s, dim@@ideal);
i3 : myStats.Histogram o3 = Tally{1 => 20} 2 => 61 3 => 17 4 => 2 o3 : Tally
The object Histogram is a symbol.