Question about Philips Hue White BT

These are the new generations, they work in two ways:
A) either in Zigbee with a bridge (the Hue bridge) and there, they have all their potential activated.
B) or in Bluetooth directly with the smartphone and a dedicated app: no need for the Hue bridge but limited functions and number of bulbs limited to 10.

You can start with just your smartphone and as soon as you get infected by the connected bulb fever, you can add a bridge and connect all your bulbs to it.

An external device (a bridge) is needed to connect everything. This is included in the kits or can be purchased separately.

See: Philips Hue White Ambiance BT (E27, 8.50W)