Example of IEnumerable and Yield

Following is very basic code snippet to create a simple IEnumerable class. (Question (1): what's the difference between IEnumerable and IEnumerator? Question (2): does anyone in this world still  implement IEnumerator?) 

using System;

using System.Collections;

public class Person

{

    public Person(string fName, string lName)

    {

        this.firstName = fName;

        this.lastName = lName;

    }

    public string firstName;

    public string lastName;

}

public class People : IEnumerable

{

    private Person[] _people;

    public People(Person[] pArray)

    {

        _people = new Person[pArray.Length];

        for (int i = 0; i <>

        {

            _people[i] = pArray[i];

        }

    }

    IEnumerator IEnumerable.GetEnumerator()

    {

        foreach (Person p in _people) 

yield return p;

    }

}

public class MyClass

{

public static void RunSnippet()

{

Person[] peopleArray = new Person[3]

        {

            new Person("John", "Smith"),

            new Person("Jim", "Johnson"),

            new Person("Sue", "Rabon"),

        };

        People peopleList = new People(peopleArray);

        foreach (Person p in peopleList)

            Console.WriteLine(p.firstName + " " + p.lastName);

}

#region Helper methods

public static void Main()

{

try

{

RunSnippet();

}

catch (Exception e)

{

string error = string.Format("---\nThe following error occurred while executing the snippet:\n{0}\n---", e.ToString());

Console.WriteLine(error);

}

finally

{

Console.Write("Press any key to continue...");

Console.ReadKey();

}

}

#endregion

}