✅ Difference between `string[]` and `IEnumerable<string>`

using System;
using System.IO;

class Program
{
  public static void Main()
  {
    foreach (string dir in Directory.GetDirectories("Settings"))
      Console.WriteLine(dir);
    
    foreach (string dir in Directory.EnumerateDirectories("Settings"))
      Console.WriteLine(dir);
  }
}