What is the Difference Between Similar But Different Things, Terms, and Objects

What is the difference between 60Hz and 120Hz

Frequency is the measure of repetitions or occurrences of anything per unit time. Frequency is a derived quantity. Its SI unit is Hertz and it is denoted as Hz. Actually, 1 Hz means the number of repetitions in one second. If a sinusoidal wave repeats itself 15 times in one second than its frequency is 15Hz. Similarly, 60 Hz and 120 Hz are the two entirely different terms.