Whenever you are dealing with a large spreadsheet, it can often be easy to click on the wrong cell and input bad data. Excel has a built-in means to prevent this bad data from being inputted known as Data Validation.
Data Validation lets you set specific rules for a cell or a group of cells. These can range from text length, whole numbers, decimals and date and time and limiting what can be put in by a list of names or objects.
You can also add a special input message if you wanted someone to input a phone number or the specific type of data you are looking to validate. This can help the user figure out what exactly they need to put in.
Data Validation helps ensure the user of your spreadsheet puts in the data you require and helps stop the spread of bad data within the spreadsheet.
