Data validation testing is a process that allows you to check whether the given data is correct and complete. It helps verify whether the value of a data item comes from the given (finite or infinite) set of acceptable values. For instance, a geographic code (field), such as a US State, may be checked against a table of acceptable values for the field.
When it comes to data validation in Excel, you can restrict the type of data or the values that users enter into a cell, such as by creating a drop-down list. Likewise, for data integration in Google Sheets, you can follow the similar technique. You can also create a data validation formula in Excel. However, manually validating data can be time-consuming and susceptible to human errors.