Newbee questions about gateways

Installation Home Assistant OS
1

Hi,
Brand new to the forum so please excuse me if I am in the wrong category.
I currently have an old “stupid” home and as we are rebuilding our kitchen I am thinking of going the “smart” way with Zigbee or Z-Wave. LED strips and spots and remote controll of our awning.

HomeAssistant sounds like a good option. Am also looking at OpenHAB. Have spent hours on the net but don’t get if a Raspberry with HA will replace all Gateways that are rcommended by different manufacturers. Seems like I need the IKEA gateway to be able to update IKEA trådfri devices and the Hue gateway if I have Hue devices and I need the Ubisys Gateway if I want to use the J1 roller switch.

Does the RPi replace all of these gateways?

Are integrations (Zigbee/Z-Wave) just a way of providing an API between HA and these devices?

What is the roll of deConz in HA? What does it provide that HA does not have?

For installing HA, it is only recommended the RPi and HA image. But how does HA communicate/find the devices? Don’t I need like a USB stick to access the Zigbee/Z-Wave radio I/F?

Sorry for all questions but this really gets me thinking if it won’t be easier staying in the “stupid” house…

Thanks,
Teebar

2

In short, HA cannot connect to lightbulbs etc without some hardware. It can connect to a Philips Hue hub, or to an Ikea and others.

I had a Hue, but replaced it with a deconz usb stick so i can use that to connect do different hardware > I have Hue bulbs, innr bulbs, Ikea remotes, Osram led strip and temp sensors from Aqara

A Hue hub can support other manufacturers bulbs as well, but I went for deconz