The saving portion is on the right side, and generates the control messages for writesf. This will be a common feature in further examples.
The noise object generates a white noise. A white noise generates frequencies in all ranges, and is important in subtractive synthesis (frequencies removed by filtering), etc.
The loadbang will create a bang when file is opened. Save it, close it, and open it. If the DSP has been checked on main console, the file will be automatically created at startup.
The mono audio showing the noise: