xaml - MVVM and WPF - how to combine sources for a DataGrid -

i new wpf/mvvm have read through lot of tutorials , done small projects have gained elementary understanding.

my problem:

i have model class holds collection of data. main view must display several of models' data on datagrid. current approach making datagrid in model's view defining datatemplate datagrid itemssource model's collection.

this approach sort of works creates datagrid each model. know of way have single datagrid?

if view should display single grid might want make viewmodel single collection , fill collection several model collections.

that viewmodel for.