Concept Of AcceptChanges() and RejectChanges()

Concept Of AcceptChanges() and RejectChanges()

 ExpressionDataSet ds;
        ExpressionDataSetTableAdapters.expressionTableAdapter sta;

        private void AcpBtn_Click(object sender, EventArgs e)
        {
            try
            {
                ds = new ExpressionDataSet();
                sta = new ExpressionDataSetTableAdapters.expressionTableAdapter();
                sta.Fill(ds.expression);
                DataRow dr = ds.expression.NewRow();
                dr ["StudentID"] = textBox1.Text;
                dr["Name"] = textBox2.Text;
                dr["English"] = textBox3.Text;
                dr["Chemistry"] = textBox4.Text;
                dr["Math"] = textBox5.Text;
                ds.expression.Rows.Add(dr);
                sta.Adapter.Update(ds.expression);
                ds.expression.AcceptChanges();
                MessageBox.Show("Stored");
            }
            catch(Exception ex)
            {
                ds.RejectChanges();
            
            }
            }