decoding qr code by c#

Question

// The QRDecoder converts byte array to text string the class using this conversion

public static string ByteArrayToStr(byte[] DataArray) {
 Decoder = Encoding.UTF8.GetDecoder();
 int CharCount = Decoder.GetCharCount(DataArray, 0, DataArray.Length);
 char[] CharArray = new char[CharCount];
 Decoder.GetChars(DataArray, 0, DataArray.Length, CharArray, 0);
 return new string(CharArray);
}

it is converting byte to string ...can anyone tell me how is it working