From First Speaker to Most Advance Wireless Speaker
The standard dynamic loudspeaker that we know of today was first built in the 1920's and uses a magnetic field to move a coil or magnet which is connected to a diaphragm.
Batteries
Wireless speakers use rechargeable battery to power them. The operating time of the speaker with more powerful batteries can last up to 10 hours or more. Almost all wireless Bluetooth speakers operate on rechargeable batteries that are not replaceable, so that the lifespan of these speakers is that of their batteries.
In order to be recharged, wireless speakers must be connected to an electrical source direct to charger or USB port.
Bluetooth
Bluetooth is a wireless technology which is found in most of today phone you can get your hands on. including in many other devices and gadgets around the home and the office, such as laptops, speakers, headphones, car mp3 connectors.
Bluetooth is used to connect devices that are in close proximity, cutting down on cables and giving you flexibility and freedom.