Using data validation in Excel means you can put restrictions on what can be entered into the cell, increasing accuracy. There are a lot of different options and settings within the data validation area. Here we have a drop down list of choices that the user can select from. You could also require the data to be a date, or a number, or just pop up a warning if the information entered is outside of set parameters. Data validation is a must if you are sharing your spreadsheet with others and you require them to enter information.

You will find Data Validation in the Data menu, in the Data Tools section.
