A common use of data validation is to create a drop-down list. Use it to restrict the type of data that users enter into an Excel cell.

Follow the steps below to create a drop-down list using data validation in Excel. If you want to add a message pop up, you can click the Input Message tab and check the checkbox for “Show input ...

Many programs take input from a user and then validate it before it is processed. It is important that the messages to the user are appropriate to reduce the risk of invalid data being entered.