What is Data Validation in Excel?

     Data Validation in Excel is a powerful feature that allows you to control what type of data can be entered into a cell or range of cells. It helps prevent invalid entries and ensures that users input data in a consistent and correct format — such as numbers within a range, specific dates, text lengths, or from a predefined list.

How to Apply Data Validation in Excel

Step-by-step Instructions:
   * Select the cell(s) where you want to apply data validation.
    *Go to the "Data" tab on the Ribbon.
    *Click on "Data Validation" in the Data Tools group.
    *In the Data Validation dialog box, under the Settings tab:
     *Choose a Validation Criteria from the Allow drop-down:
            Whole number
            Decimal
            List
            Date
            Time
            Text length
            Custom (using formulas)
    *Set the specific conditions (e.g., between 10 and 100).
    Optionally:
     *Go to the Input Message tab to display a message when the cell is selected.
      *Go to the Error Alert tab to set a message that appears if invalid data is entered.
    *Click OK.