Home Assistant is very flexible. It's kind of like a common meeting ground where all the things come together in one spot, and they can thereafter be programmatically automated.

Cameras? NVRs? A sea of IoT light bulbs, switches, and sensors that all variously speak Zigbee or Matter or Thread or Wifi or Z-Wave or Bluetooth or some clown connection or whatever? Almost all of it works fine with HA. It's very flexible.

If anything, it may be too flexible. It can be rough getting started with it.

(I use it in "Home Assistant OS" form in a VM on a light-weight x86 box that only cost me $50, wherein: Performance is quite lovely, and updates haven't hosed anything up [yet] that required me to go poking at it to keep it going. It's also right at home on bare-metal x86, or an ARM SBC like a Raspberry Pi, or in containers, or [...]. Did I mention that it's flexible?)

Home assistant just connects to the devices; you still need the devices to make it useful.