We call Bluetooth today was first introduced back in 1989 dr. Nils who was the chief technology officer at Ericsson mobile and inventor Johann Ullman had this revolutionary idea to develop a pair of wireless headsets because well let's be honest cords and wires are annoying it was a major undertaking so they brought dr.Yap Hartson on to the project a mere five years later he'd be the engineer who made the breakthrough and came out with the first protocol it took a few more years to perfect the technology but finally in 1999 they presented their first hands-free headset to the world at the COMDEX computer exposition and trade show in Los Vegas they even won Best in Show.sometimes things that happen in Vegas don't necessarily stay in Vegas after all well this thing was dubbed Bluetooth which then begs the question where does the strange name come from well at the time three companies were working separately to create short-range radio technologies that would connect computers and different devices using shortwave frequencies but since the invention was in its early stages Intel Ericsson and Nokia decided that the best way to proceed was to create a single Wireless standard gym hardac who was working for Intel happened to be reading a historical book about the Viking King Harald Bluetooth grandson United Denmark in Norway that story inspired hardac to propose his idea of calling this single short link device that would unite communications Bluetooth so that was it and in case you're wondering how they  got the nickname that he had a rotten tooth that looked kind of bluish anyway they paid tribute to the great Viking King when they came up with the logo just looks like a bee but if you examine it a little closer and you happen to know the Nordic alphabet then you'll see that the logo is formed from two different symbols they represent the initials of the King H and B for Harald Bluetooth works a lot like Wi-Fi it uses radio wave to send data between devices at short distances now whereas Wi-Fi uses radio waves to transmit data between your router where your Wi-Fi comes from and your device bluetooth does it between devices.
So basically if two things have a Bluetooth option then they can transmit data between each other this communication of sorts is measured in gigahertz for both Bluetooth and Wi-Fi it's usually at the 2.4 gigahertz frequency that means those radio waves even though Bluetooth still works at the 2.4 gigahertz frequency just like Wi-Fi it mostly works at shorter distances and uses much weaker signals just 1 milliwatt of power the cool thing is that Bluetooth can connect to eight devices at the same time without any interference from other wireless items here's a real-life example let's say you're listening to music from your laptop using your wireless headphones and you're also typing on your computer with your wireless keyboard the Bluetooth transmitters in both your computer and your devices use 79 different frequencies in that range to prevent your music from getting in the way of your keyboard it changes frequencies 1600 times every second when you try to connect the Bluetooth device with your phone then a sort of conversation takes place between the two of them they present their data and decide on whether they need to exchange information .
 If one of them needs to control the other to do what after this short digital dialogue ends and the two devices agree on their roles they connect together to form a network that Bluetooth network of connected devices is called a piconet once their connection is established they begin their frequency hopping in order to continually stay connected and avoid interference you can even take a device with you to another room and it'll keep working as long as you don't go too far. Bluetooth is such a huge part of our everyday lives yet most of the time it goes unnoticed so if you're wondering what devices use bluetooth nowadays the answer is almost all of them phones, headphones,earbuds,speakers,stereos ,TVs,cameras,cars, tablets, game consoles,etc. 

Bluetooth speaker has its own conversation going with your phone and the best part is that none of them so rudely intervene in the others conversations that's not only thanks to frequency hopping it's also because each device has its own address programmed by the manufacturer so even if your wireless mouse gets a message from your TV it'll just automatically ignore it because they have different addresses but the way Bluetooth works raises a few security questions as well just like all wireless networking setups there's always the legitimate concern of sending personal data through radio waves and that data falling into the wrong hands when Bluetooth first came out it was really easy for someone to access your data without your permission but over time this technology has become more secure Bluetooth manufacturers are aware of the risks so they've already done a lot to make devices more protected against security threats you see in almost all of our personal gadgets there's the trusted devices option that enables you to share data without permission while others need permission to access your device but let's not forget about spam there's this trend called bluejacking where a person or company can send you their electronic business card or an ads as a text message using bluetooth of course when you see that you either ignore it or panic but this is something that mostly happens in public places where everyone is using their phones you can prevent it from happening to you by making your Bluetooth device non discoverable when you're out and about and if it does happen to you don't worry just turn your Bluetooth off and remove the attackers device from your trusted ones now with those blue hackers busted let's talk about the health concerns unfortunately there's not enough evidence and research done on Bluetooth to determine if it's harmful for people or not and it's also quite tricky because Bluetooth waves are just one part of the wireless smog that surrounds us every single day but perhaps this will be comforting to know the amount of non ionizing radiation present and Bluetooth headphones is a lot less than what's in a typical cell phone so if you're worried about Bluetooth affecting your health you should probably give up your phone first and still your phone isn't a cause for alarm either there are regulatory organizations put in place to keep the public safe from being exposed to too many radio frequencies from our devices for example the Federal Communications Commission checks that cell phone manufacturers don't sell devices that go over what scientists say is the limit of how many radio frequencies the human body can absorb from one gadget that number is called the specific absorption rate SAR and you can always check which models have the lowest if you're in the market for a phone so don't worry too much about it the health aspect is always under check and is constantly being studied all in all I still say Bluetooth is a lot better than getting tangled up in cords and having to change CDs or cassette tapes in your car.