How to handle conditional dropdown lists

1. How do I add an IF condition to a drop down list?
2. What is conditional drop down?

How do I add an IF condition to a drop down list?

In the Ribbon, select Data > Data Tools > Data Validation. Select List from the Allow drop-down list, and then select Range F2:I2.

What is conditional drop down?

A conditional dropdown is a list whose items depend on a selection in another field. These items change depending on what a user selects in another list. For example, a conditional dropdown for employees could list only certain cities because in another field, a particular country was selected.