using System;

using System.Collections.Generic;

public class Parent

{

    public string DatabaseServer { get; set; } = "ParentServer";

}

public class Child : Parent

{

    public Child() { DatabaseServer = "Child"; }

}

​

public class Program

{

    public static void Main()

    {

        Parent parent = new Parent();

        Console.WriteLine(parent.DatabaseServer); // Output: ParentServer

        Child child = new Child() { DatabaseServer = "Child Other" };

        Console.WriteLine(child.DatabaseServer); // Output: Child Other

        Parent childAsParent = new Child();

        Console.WriteLine(childAsParent.DatabaseServer); // Output: Child

        List<Parent> collection = new();

        collection.Add(parent);

        collection.Add(child);

        collection.Add(childAsParent);

        collection.Add(new Parent());

        collection.Add(new Child());

        collection.Add(new Child() {DatabaseServer = "Another"});

        Console.WriteLine();

        foreach(Parent p in collection)

            Console.WriteLine(p.DatabaseServer); 

    }

}