Learning Oop c# and cant seem to link the two pages (Doing a college assessment)

where i have ** ** is where the problem is, " new Bankaccount is red and underlined in vs"

namespace BankAccount_Question2
{
    public class Program
    {
         static void Main(string[] args)
        {

            Console.OutputEncoding = System.Text.Encoding.UTF8;

            **var customer = new Bankaccount();**

            Console.Write("Enter your name :");
            string name = Console.ReadLine();

            Console.Write("Enter your ID number :");
            string number = Console.ReadLine();

            Console.Write("Enter you bank balance :");
            string balance = Console.ReadLine();
            Console.WriteLine();

            customer.Name = name;  
            customer.AccountNumber = number;
            customer.Balance = balance;

            Console.WriteLine(customer.ToString());
            
        }
    }
}

Please define link and define pages. I do not understand what those are in this context.

I think the problem is that Bankaccount is not defined. What is Bankaccount? As best as I can tell Bankaccount is a class. Where is the definition of it?

Also, I think that:

Console.WriteLine(customer.ToString());

will not do what you want it do unless Bankaccount overrides ToString.