Explanation
Data Validation controls what users are allowed to enter into a cell.
It helps prevent incorrect or unwanted data.
Go to:
Data → Data Validation
Common Validation Types
- Whole Number
- Decimal
- List
- Date
- Time
- Text Length
- Custom Formula
Example
For an Age column, you can allow only numbers between 18 and 60.
Practice
Create an Employee Registration sheet and decide which fields need validation.