Excel’s Application object’s WorksheetFunction property is a container for Microsoft Excel worksheet function. This property returns a WorksheetFunction object that allows VBA access to the rich set of functions that are built into Excel. While VBA has some generic functions of its own, Excel’s set is much bigger, and more suited for (you guessed it) Excel. As soon as you type in the dot after WorksheetFunction, you will see a list of Excel functions that you can use in your VBA code. But do you really need the WorksheetFunction object?
There are two collections in Excel-VBA that lets the user access sheets in a workbook: the Sheets collection and the Worksheets collection. You can use these collections interchangeably in most situations, but they were each created for a specific purpose. Read on if you’d like to know more about why Microsoft created those two collections and their purpose.