series connection and parallel of led

series connection and parallel of led
The series connection have an advantage over the parallel connection on circuit design . Why is this?
We are making further investigations and will take the parallel connection of led from there . The VF(Forward Voltage)have been varied. Differences also exist between different VF of the same batch of LED. the forward Voltage changes Along with the rise of temperature and work current, so the parallel connection of LED is not recommended.
series and parallel of led