how will I update my datagrid per row and will automatically updated also in database

i apologize in advance for my English, by the way i just need help of how will i update my DataGrid. I have a datagrid with 21 columns, and i just want to update it per row, and its just that everytime i click inside the datagrid its just one cell that is highlightened, what i wanted to do is when i click a cell the whole one row including the cell i clicked will be highlightened and every cell will be ready to change and will be updated, also in database.
i just a beginner of vb.net, so i really can't understand some features without help by others. :)

thanks in advance, Godbless