Both the data sets are on Y-axis, but the second data set is added as a secondary axis to the same chart. Sales amounts are shown in blue bars, whereas Targets are shown in the orange line represented in the vertical axis as shown above. When a secondary axis is added, the graph will look like this, as shown below.
This data has two datasets I,e Sales and Target Achieved %. You can download this Add a Secondary Axis Excel Template here – Add a Secondary Axis Excel Template