CFL Ballast Circuit

Hi
Please explain ballast circuit operation with voltage and current direction on schematic circuit.
Also the waveform of the input and output of the circuit.

Normally you only show the value of voltages on various points in a circuit.

Once you have the voltage-values, the current will flow from a point of high potential (high voltage) to a lower potential.
However, because the circuit above is driving a lamp from an AC supply, the current will be constantly increasing and then decreasing at 100 or 120 times per second.

When the voltage enters the high frequency section of the circuit, the frequency of operation is about 100kHz and the current rises and falls at this higher frequency.