I Have Two Column In The Datagrideview I Want Enter Some Value To First Column But Then Both Of Them The Same Should Have The Same Value

Just write code in datagridview_cellvaluechanged event like below . And after entering value click in any cell except that cell in which you have just entered text or value then you will see that the same value is in the other column in the corresponding row

private void dataGridView1_CellValueChanged(object sender, DataGridViewCellEventArgs e)
{

        if (e.ColumnIndex == 0 && e.RowIndex>-1)
        {
            dataGridView1[e.ColumnIndex + 1, e.RowIndex].Value = dataGridView1[e.ColumnIndex, e.RowIndex].Value;

        }

}