Plz any one help me in understanding this code

Private Structure MMIOINFOPublic
    Public dwFlags As Integer : Public fccIOProc As Integer : Public pIOProc As Integer : Public wErrorRet As Integer
    Public htask As Integer : Public cchBuffer As Integer : Public pchBuffer As String : Public pchNext As String
    Public pchEndRead As String : Public pchEndWrite As String : Public lBufOffset As Integer : Public lDiskOffset As Integer
    Public adwInfo1 As Integer : Public adwInfo2 As Integer : Public adwInfo3 As Integer : Public adwInfo4 As Integer
    Public dwReserved1 As Integer : Public dwReserved2 As Integer : Public hmmio As Integer
End Structure
Private Structure WAVEHDRPublic
    Public lpData As Integer : Public dwBufferLength As Integer : Public dwBytesRecorded As Integer : Public dwUser As Integer
    Public dwFlags As Integer : Public dwLoops As Integer : Public lpNext As Integer : Public Reserved As Integer
End Structure
Private Structure WAVEINCAPSPublic
    Public wMid As Short : Public wPid As Short : Public vDriverVersion As Integer : Public szPname As String : Public dwFormats As Integer : Public wChannels As Short
End Structure
Private Structure WAVEFORMATPublic
    Public wFormatTag As Short : Public nChannels As Short : Public nSamplesPerSec As Integer : Public nAvgBytesPerSec As Integer
    Public nBlockAlign As Short : Public wBitsPerSample As Short : Public cbSize As Short
End Structure
Private Structure MMCKINFOPublic
    Public ckid As Integer : Public ckSize As Integer : Public fccType As Integer : Public dwDataOffset As Integer : Public dwFlags As Integer
End Structure
Private Structure MMTIMEPublic
    Public x As Integer
End Structure

Private Structure MMIOINFOPublic
    Public dwFlags, fccIOProc, pIOProc, wErrorRet, htask, cchBuffer, lBufOffset, lDiskOffset, adwInfo1, adwInfo2, adwInfo3, adwInfo4, dwReserved1, hmmio As Integer
    Public pchBuffer, pchNext, pchEndRead, pchEndWrite As String
End Structure
Private Structure WAVEHDRPublic
    Public lpData, dwBytesRecorded, dwUser, dwFlags, dwLoops, lpNext, Reserved As Integer
End Structure
Private Structure WAVEINCAPSPublic
    Public wMid, wPid, wChannels As Short
    Public vDriverVersion, dwFormats As Integer
    Public szPname As String
End Structure
Private Structure WAVEFORMATPublic
    Public wFormatTag, nChannels, nBlockAlign, wBitsPerSample, cbSize As Short
    Public nSamplesPerSec, nAvgBytesPerSec As Integer
End Structure
Private Structure MMCKINFOPublic
    Public ckid, fccType, dwDataOffset, dwFlags As Integer
End Structure
Private Structure MMTIMEPublic
    Public x As Integer
End Structure