A cumulative frequency graph, also known as an ogive, is a curve showing the cumulative frequency plotted on the y-axis against a set of data on the x-axis. To draw an ogive, you calculate the cumulative frequency and plot it to create a curve representing the cumulative total of frequencies up to each data point. There are two types of ogives - less than and more than - which are drawn using the same process but represent frequencies below or above each data value.