Explanation of "Class.forName" and "Connecton con = DriveManager.getConnecton"

Could someone explain to me the relavancy/pupose of the following two line of code, in the excerpt of code below?

Class.forName ("sun.jdbc.odbc.JdbcOdbcDriver");
Connection con = DriverManager.getConnection (url);



import java.sql.*;
public class P5 {
      public static void main (String args[]) {

            String url = "jdbc:odbc:P4";

            Class.forName ("sun.jdbc.odbc.JdbcOdbcDriver");
Connection con = DriverManager.getConnection (url);
Statement stmt = con.createStatement ();
String query = "SELECT ENO FROM Employee";
ResultSet rs = stmt.executeQuery (query);
while (rs.next())
{
        String eno = rs.getString("ENO");    
        System.out.println(eno);
}
      }
}