Mixed voltage designs
Your design could have as many as 5 or 6 different supply voltages, which will complicate the power distribution routing.
There are two choices in where to generate the secondary voltages
Generate all voltages centrally at the power supply and distribute across the PCB (best when different sections of the board need that voltage)
Locate the generation circuit near the components that require that voltage (best if one or two ICs need that voltage)