C# Selection Sort example need to be explained

Question

I face some problems to understand sort example so that i am just wondering if some one give me a hand and explain it to me
Thank you for your assistant
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using System;

class TestSelectionSort;

{

  public static void Main( )

  {

    int[] sortArray = {7, 3, 66, 3, -5, 22, -77, 2};

    SelectionSort(sortArray);

    foreach (int element in sortArray)

      Console.Write(element + "\t");

    Console.WriteLine();

  }

// Include remaining code here

} // end TestSelectionSort

 

 

// sort using the selection sort algorithm

 static void SelectionSort(int[] data)

 {

    int next, indexOfMin;

    for (next=0; next<data.Length - 1; next++)

    {

      indexOfMin = Min(data,next,data.Length-1);

      Swap(data, indexOfMin, next);

    }

 }

 

 

 

 

// find the smallest element in a specified range

  static int Min(int[] data, int start, int end)

  {

    int minIndex = start;

    for (int i = start + 1; i <= end; ++i)

      if (data[i] < data[minIndex])

        minIndex = i;  // found a smaller value

    return minIndex;

  }

 

 

 

static void Swap(int[] data, int first, int second)

  {

    int temp;

    temp = data[first];

    data[first] = data[second];

    data[second] = temp;

  }