Excel host items are classes that offer programming models for developing document-level solutions using VSTO. Document-level customization uses a set of host items that includes
Microsoft.Office.Tools.Excel.Worksheet. Worksheet host is one of the host items that acts as a container for controls such as Windows form controls.
In Excel, you have three types of host items:
In every Excel solution, there is one workbook host item and a separate worksheet host item for each worksheet in the workbook. All of these host items are folded in the native Excel workbook, Excel worksheet, and the Excel ChartSheet, ...