Passive speakers are the easiest to understand--they're the speakers we all grew up with, and they're the speakers you need to complete a traditional audio system. They have no power supply of their own and need to receive an amplified electrical signal in order to function. So you don't plug them into the mains--instead, you wire them to an amplifier that provides the electrical impetus they need to create sound. Bluetooth, as you know, is a method of wirelessly streaming audio information--so a Bluetooth speaker has its own power supply (from the mains or batteries) and amplification, and once it receives a Bluetooth signal it can decode it and turn it into sound. A wireless speaker has its own source of power and its own amplification--and there's every chance it will be able to deal with a Bluetooth signal. But in addition, it can deal with audio information using a Wi-Fi network or cloud storage--so if you subscribe to a streaming service, its cloud-based service (such as Spotify Connect) is available without the need for a Bluetooth connection.