class DisconnectedDataform : Form{ private SqlConnection conn; private SqlDataAdapter daCustomers; private DataSet dsCustomers; private DataGrid dgCustomers; private const string tableName = “Customers”; // initialize form with DataGrid and Button public DisconnectedDataform() { // fill dataset Initdata(); // set up datagrid dgCustomers = new DataGrid(); dgCustomers.Location = new Point(5, 5); dgCustomers.Size = new Size(this.ClientRectangle.Size.Width – 10, this.ClientRectangle.Height – 50); dgCustomers.DataSource = dsCustomers; dgCustomers.DataMember = tableName; // create update button Button btnUpdate = new Button(); btnUpdate.Text = “Update”; btnUpdate.Location = new Point(this.ClientRectangle.Width/2 – btnUpdate.Width/2, this.ClientRectangle.Height – (btnUpdate.Height + 10)); btnUpdate.Click += new EventHandler(btnUpdateClicked); // make sure controls appear on form Controls.AddRange(new Control { dgCustomers, btnUpdate }); } // set up ADO.NET objects public void Initdata() { // instantiate the connection conn = new SqlConnection(“Server=(local);DataBase=Northwind;Integrated Security=SSPI”); // 1. instantiate a new DataSet dsCustomers = new DataSet(); // 2. init SqlDataAdapter with select command and connection daCustomers = new SqlDataAdapter(“select CustomerID, CompanyName from Customers”, conn); // 3. fill in insert, update, and delete commands SqlCommandBuilder cmdBldr = new SqlCommandBuilder(daCustomers); // 4. fill the dataset daCustomers.Fill(dsCustomers, tableName); } // Update button was clicked public void btnUpdateClicked(object sender, EventArgs e) { // write changes back to DataBase daCustomers.Update(dsCustomers, tableName); } // start the Windows form static void Main() { Application.Run(new DisconnectedDataForm()); }}It is a wide topic so we can not understand it within a blog. It consists of different approaches that help to achieve the desired task, so we will discuss them later.I hope this blog will help to get some basic idea of working in .NET both connected and disconnected environment and feel free to comment your questions below.