Iron Excel reads data from a worksheet by opening the workbook, selecting the worksheet, and programmatically cycling through the cells. IronExcel is native C# VB .NET and does not require Office Interop. This makes it significantly more efficient in operation and easier to deploy because Microsoft Office does not need to be installed on the target machine or server. https://ironsoftware.com/csharp/excel/tutorials/how-to-read-excel-file-csharp/