Switching on and off is possible but dimming is only possible with the app or the Philips dimmer switch for Hue.

It is not only possible to switch on/off. Contrary to other statements in the comments, you can also dim the bulbs with an ordinary dimmer switch. Without the bridge, the bulb is just an ordinary LED lamp.

As already mentioned above: Switching on/off at the switch yes, dimming is only possible with an app (but also automated).

Switching on and off yes. I cannot say anything about dimming, but I thought I had read that this does not work with a normal dimmer. If the power was disconnected from the lamp by switching it off and on again, the lamp lights up in warm white.

yes they can. operation also possible via app