I was trying to figure out the BT Address of a device and then got in trouble while finding that it follows IEEE 802-2014 standard as well as MAC Address hence which is the difference within MAC Address and BT Address:
Can a phone device (let's say) have BT Address and MAC Address?
If so which would be the impact of having either same MAC Address or BT Address within 2 devices?
Bluetooth addresses are indeed drawn from the same space as the MAC addresses you might be more familiar with -- those on Ethernet adapters or 802.11 WiFi interfaces. In order to assign an address to a Bluetooth interface on say, a phone, the manufacturer must purchase the right to do so from the IEEE in the same way that they must register some portion of the space to assign MAC addresses to 802.11 interfaces. Because of this, it's common to say "Bluetooth MAC", at least in my own experience. The Bluetooth Core Specification says this:
The BD_ADDR shall be created in accordance with Section 9.2 (“48-bit univer-
sal LAN MAC addresses”) of the IEEE 802-2001 standard (http://stan-
dards.ieee.org/getieee802/download/802-2001.pdf) and using a valid
Organizationally Unique Identifier (OUI) obtained from the IEEE Registration
Authority (see http://standards.ieee.org/regauth/oui/forms/ and sections 9 and
9.1 of the IEEE 802-2001 specification).
If a phone has both a Bluetooth and 802.11 chipset, it must have unique hardware identifiers for both. In practice, what I have seen is that manufacturers will assign MAC address X to the 802.11 interface, and MAC address X+1 to the Bluetooth interface on the same phone or vice versa; for example, WiFi MAC 00:11:22:33:44:00 and Bluetooth MAC 00:11:22:33:44:01. There's nothing stating that they must do this, but it seems to be a pretty standard way of divvying up their IEEE allocations.