How do we differentiate between a signal netclass and power netclass?

How do we determine he<img class="content-img"

Usually anything that powers the IC, powers a transistor/MOSFET or supply power to drive a high current component is considered the power net.

Signal nets are somethings that carries smaller current to turn on transistor/MOSFET gate, logic decision taken by a IC, or basically any signal that carries information is considered as the Signal net.

According to your attachment :

  • VDDA, VSSA, VDDB, VSSB, +5v, GND can be considered as power nets
  • Disable, PWM signals can be considered as signal nets