Hello Wilson,

Thank you for posting in our community.

The Model1 and Model2 used in this context are the model types that will be used when constructing the grid.

For example in the code snippet below Customer is the class that will be passed in the template and it can be used later when creating the columns in chaining and etc. 

@(Html.Infragistics().Grid<Infragistics.Web.Mvc.Samples.Models.Customer>(Model) 

 ...

public class Customer

    {

        public int CustomerID { get; set; }

        public string CustomerName { get; set; }     

        public List<Order> Orders { get; set; }

    }

…..

   .Columns(column =>

        {

            column.For(x => x.CustomerID).HeaderText(“CustomerID”);

        })

More examples how this is used you can find in the online samples and the help documentation

http://igniteui.com/grid/datatable-binding

http://help.infragistics.com/Help/Doc/jQuery/2013.2/CLR4.0/html/igHierarchicalGrid_Binding_to_DataSet.html#_Toc335726982

Please let me know if you need further assistance regarding this.