**Frequency** means how many times a certain value appear in a dataset.

**Relative Frequency** means how many times a certain value occur relative to all the rows in a dataset.

**Cumulative frequency** tells us how many observations are below a certain value in a dataset. To calculate it, add each frequency in a table to the sum of the ones before it.

In a dataset of students' scores (85, 92, 78, 90, 85, 88, 92, 78, 85, 90), the frequency of each score shows how many times it appears. 78 occurs twice, 85 thrice, 88 once, 90 twice, and 92 twice.

Relative frequency means the occurrence of each score relative to the total number of scores (10 in this case), with 78 at 0.2, 85 at 0.3, 88 at 0.1, 90 at 0.2, and 92 at 0.2.

Cumulative frequency shows the number of observations below a certain value. The cumulative frequency of 85 is 5 which means that five scores are 85 or lower so the cumulative relative frequency is 5/10=0.5.