Прокоментировать представленный код

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dim a as integer //описание переменных
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Imports System.IO
Imports System.Text
Imports System.Security.Cryptography
Public Class TextEncrypt
    Dim DES As New TripleDESCryptoServiceProvider
    Dim MD5 As New MD5CryptoServiceProvider
    Private Sub btn_back_Click(sender As Object, e As EventArgs) Handles btn_back.Click
        Me.Close()
    End Sub
    Private Sub btn_encrypt_Click(sender As System.Object, e As System.EventArgs) Handles btn_encrypt.Click
        DES.Key = MD5Hash(txt_key.Text)
        DES.Mode = CipherMode.ECB
        Dim Buffer As Byte() = UTF8Encoding.UTF8.GetBytes(txt_originalText.Text)
        txt_encryptText.Text = Convert.ToBase64String(DES.CreateEncryptor().TransformFinalBlock(Buffer, 0, Buffer.Length))
    End Sub
    Function MD5Hash(ByVal value As String) As Byte()
        Return MD5.ComputeHash(UTF8Encoding.UTF8.GetBytes(value))
    End Function
End Class

Imports System.IO
Imports System.Text
Imports System.Security.Cryptography
Public Class TextDecrypt
    Dim DES As New TripleDESCryptoServiceProvider
    Dim MD5 As New MD5CryptoServiceProvider
    Private Sub btn_back_Click(sender As Object, e As EventArgs) Handles btn_back.Click
        Me.Close()
    End Sub
    Private Sub btn_decrypt_Click(sender As System.Object, e As System.EventArgs) Handles btn_decrypt.Click
        Try
            DES.Key = MD5Hash(txt_Key.Text)
            DES.Mode = CipherMode.ECB
            Dim Buffer As Byte() = Convert.FromBase64String(txt_encryptText.Text)
            txt_originalText.Text = UTF8Encoding.UTF8.GetString(DES.CreateDecryptor().TransformFinalBlock(Buffer, 0, Buffer.Length))
        Catch ex As Exception
            MsgBox("Неправильный ключ!")
        End Try
    End Sub
    Function MD5Hash(ByVal value As String) As Byte()
        Return MD5.ComputeHash(UTF8Encoding.UTF8.GetBytes(value))
    End Function
End Class

Dim Buffer As Byte() = UTF8Encoding.UTF8.GetBytes("СЮДА ЗАПИХИВАЕШ")'кодирование 13 строка
Dim Buffer As Byte() = Convert.FromBase64String("СЮДА ЗАПИХИВАЕШ")'декодирование 14 строка