how to Linq to SQL by code in C# (connect to sql by code)

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C#

Good Day
i have used ADO.net to connect and manage data in SQL server and now i knew about Linq and i want to use it but i prefer to do everything by code only,so if you please i want to write the following simple code in the LINQ method:

SqlConnection oConn = new SqlConnection("Data Source = roger\\sqlexpress;Initial Catalog = test; Integrated security=SSPI");
SqlCommand oCmd = new SqlCommand();
SqlDataReader Rdr;
            
oConn.Open();
            
oCmd.Connection = oConn;
oCmd.CommandType = CommandType.Text;
oCmd.CommandText = "select * from person";
            
Rdr = oCmd.ExecuteReader();
while(Rdr.Read())
    MessageBox.Show(Rdr["pin"].ToString());            
oConn.Close();

and i want to know the difference between using ADO and LINQ.
Thanks