Introduction:

IEnumerable is the most basic interface for iterating over a collection, providing a generic way to traverse through elements. On the other hand, List is a concrete implementation of ICollection and IList interfaces, offering additional features such as random access and dynamic resizing.

To convert an IEnumerable to a List, you can use the List constructor that accepts an IEnumerable parameter. 

using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static void Main()
    {
        IEnumerable<int> numbers = Enumerable.Range(1, 7);
        List<int> numberList = new List<int>(numbers);

        Console.WriteLine("Converted List:");
        foreach (var num in numberList)
        {
            Console.WriteLine(num);
        }
    }
}

Output:

Converted List:
1
2
3
4
5
6
7

This program we will use an IEnumerable<int> collection to generate the numbers using Enumerable.Range method. Then, we will initialize a new List<int> by passing the IEnumerable collection as an argument to the List constructor. Finally, we will use the foreach to print the output from the numberlist.