sorry for the stupid question first of all.
I know that GPIO pins can supply 3.3V and i must try to draw max of 16mA from a single pin.
My question is about pin 1, 2, 4 (3.3V, 5V, 5V) - what i need them for? For example i can light a LED from any GPIO pin, why i need #1 - 3.3V pin since i already have all the other GPIOs that can supply 3.3V anyway?
And what about 5V pins - what should or can be used for?
Sorry again but i dont get how are they different from the rest of the general purpose pins..