ช่วยอธิบายโค้ด C# ให้หน่อยน่ะค่ะ....เพิ่งเริ่มศึกษาค่ะ

public partial class Form1 : Form
    {
        // Declare Function

        [DllImport("coredll.dll")]
        public static extern IntPtr CreateFile(String lpFileName, UInt32 dwDesiredAccess, UInt32 dwShareMode, IntPtr lpSecurityAttributes, UInt32 dwCreationDisposition, UInt32 dwFlagsAndAttributes, IntPtr hTemplateFile);
 
       [DllImport("coredll.dll")]
        public static extern bool DeviceIoControl(IntPtr hDevice, UInt32 dwIoControlCode, Byte[] lpInBuffer, UInt32 nInBufferSize, Byte[] lpOutBuffer, UInt32 nOutBufferSize, ref UInt32 lpBytesReturned, IntPtr lpOverlapped);
   
     [DllImport("coredll.dll")]
        public static extern bool CloseHandle(IntPtr hDevice);