Each new version of Bluetooth technology brings about improvements and new features. Here are some of the advances in each version:

- Bluetooth 1.0 and 1.1 introduced the basic functionality of Bluetooth, including the ability to connect devices wirelessly and transfer data.

- Bluetooth 1.2 added faster data transfer rates, adaptive frequency hopping to reduce interference, and support for improved audio quality with the Headset Profile (HSP) and Hands-Free Profile (HFP).

- Bluetooth 2.0 + EDR (Enhanced Data Rate) increased the maximum data transfer rate to 3 Mbps and introduced a new feature called Enhanced Power Control for better power management.

- Bluetooth 2.1 + EDR added features like Secure Simple Pairing (SSP) for improved security, better power management with Extended Inquiry Response (EIR), and support for Near Field Communication (NFC) for easier pairing.

- Bluetooth 3.0 + HS (High Speed) added technology called Bluetooth over 802.11 (alternatively known as Wi-Fi Direct) for faster data transfer rates up to 24 Mbps.

- Bluetooth 4.0 introduced low energy technology known as Bluetooth Low Energy (BLE), which is designed for low-power devices and extended battery life.

- Bluetooth 4.1 added better coexistence with other wireless technologies and support for IPv6 addressing.

- Bluetooth 4.2 added improved security with Privacy Feature, support for a faster data transfer rate of 2 Mbps, and better interoperability with other wireless technologies.

- Bluetooth 5.0 introduced improvements in range, speed, and capacity, such as a maximum transfer rate of 2 Mbps, four times the range of Bluetooth 4.2, and support for broadcasting to multiple devices.

- Bluetooth 5.1 added direction finding capabilities to support location-based services and improved accuracy in position tracking.

These advancements highlight the continuous improvements and progress that the Bluetooth technology is making towards better and innovative solutions that cater to the needs of wireless communication.

The specifications for Bluetooth technology are quite extensive and evolve with each new version. However, to give you a good overview, here are some key points:

Core Technology:

• Radio frequency: Utilizes the 2.4 GHz ISM band.
• Range: Typically up to 30 meters (100 feet) for Classic Bluetooth, less for Bluetooth Low Energy (LE).
• Data rates: Vary depending on version, ranging from 1 Mbps for Classic Bluetooth to 2 Mbps for Bluetooth 5.2 LE.
• Security: Employs various encryption and authentication methods for secure communication.
• Topology: Supports point-to-point, point-to-multipoint, and mesh networking configurations.

Key Versions:

• Classic Bluetooth: The original version, mainly used for voice and audio streaming.
• Bluetooth Low Energy (LE): Introduced in version 4.0, focuses on low power consumption for wearables and smart devices.
• Bluetooth 5 and 5.2: Enhance data rates, range, and performance of both Classic and LE connections.

Additional Features:

• Multiple profiles: Defines how devices interact for specific purposes like audio, data transfer, human interface devices, etc.
• Advanced Audio Distribution Profile (A2DP): Enables high-quality stereo audio streaming.
• Audio Video Remote Control Profile (AVRCP): Allows remote control of connected devices.
• Low Latency Isochronous Streams (LLISO): Reduces audio or data delay for time-sensitive applications.
• Privacy features: Bluetooth 4.2 and later versions offer enhanced privacy protections.

“Something” cannot just turn into Bluetooth. Bluetooth is not just a label - although it is also a label. But this label requires installed Bluetooth radio chip, antenna etc, since it is a radio technology.

Bluetooth is a standard to connect devices over short distance, using 2.4 GHz ISM frequencies (same as WiFi 2.4). You can connect up to 8 devices within a few meters; ad hoc communication is also possible.

Bluetooth was initially developed by Ericsson, and later put into public domain. The IEEE has taken the Bluetooth Standard under their umbrella as 802.15.1. The Bluetooth Special Interest Group (SIG) manages the standard, and certifies products. The definition of Bluetooth 1, 2, 3, 4, 5 are to them.

Your product has to go through the Branding Enforcement process, in order to use the trademark.

Most of the wireless keyboards and mice out there are actually technically BlueTooth, with a protocol framing identifier changes, so that they don’t show up as a Bluetooth device.

It’s cheaper to include the little dongle, than it would have been to go through the Branding Enforcement process, which would likely add between $10 and $15 to the price of each unit, simply to be able to call it Bluetooth.

So essentially, Bluetooth, per se, is a branding program:

For a company to use the trademarks, two things must happen:

1. a company must be a member of the Bluetooth SIG
2. The goods offered must have completed the Bluetooth Qualification Process under the member company’s account that is marketing and selling the product

It’s silly, but that’s what the SIG requires, even though Ericsson, in theory, put it in the public domain.

Bluetooth technology has evolved significantly since its inception, with major updates enhancing its capabilities, efficiency, and application scope. Here's a brief overview of its evolution:

- **Bluetooth 1.0** introduced the basic wireless communication framework, but faced compatibility and security issues .

- **Bluetooth 1.1** became part of the IEEE 802.15.1 standard, addressing some of the initial problems .

- **Bluetooth 1.2** improved security with features like Adaptive Frequency Hopping (AFH) and Extended Synchronous Connection-Oriented links (eSCO) .

- **Bluetooth 2.0** increased the data transfer rate to 3 Mbps with the Enhanced Data Rate (EDR) feature .

- **Bluetooth 2.1** added energy-saving features and Simple Secure Pairing (SSP) for easier device pairing .

- **Bluetooth 3.0** introduced High Speed, leveraging 802.11 WiFi for data transfer rates up to 24 Mbps .

- **Bluetooth 4.0** marked a significant shift with the introduction of Bluetooth Low Energy (BLE), focusing on low power consumption and three operational modes: BLE, traditional Bluetooth, and high-speed Bluetooth .

- **Bluetooth 4.1** improved interoperability with LTE and introduced IPv6 support for cloud synchronization .

- **Bluetooth 4.2** increased data transfer speed and enhanced privacy protection .

- **Bluetooth 5.0** boosted data transfer rates, extended range, and increased broadcast capacity, introducing mesh networking for IoT .

- **Bluetooth 5.1** added direction-finding capabilities, improving location services with angle of arrival (AOA) and angle of departure (AOD) technologies .

- **Bluetooth 5.2** introduced LE Isochronous Channels, Enhanced ATT, and LE Power Control, further refining low power consumption and audio quality .

- **Bluetooth 5.3** continued to enhance transmission efficiency, security, and stability, improving upon the capabilities of Bluetooth 5.2 .

Each generation of Bluetooth has built upon the last, with a focus on increased speed, range, efficiency, and the support of new use cases, especially in the realm of the Internet of Things (IoT) 。

Bluetooth uses radio waves to communicate between two devices; that’s why they call it a “Bluetooth radio.” The Bluetooth protocol works by two devices “pairing” - exchanging information about one another and remembering eachothers’ unique “physical addresses.” For security, as I’m sure you’ve seen, most devices have you enter a code so that you can prove that it is you who is attempting to connect and not someone else nearby (say you’re connecting your phone to your car, your car or phone will typically ask you if the code looks correct.)

Both devices usually have the ability to both transmit and receive. When you enter “pairing mode” or “discovery mode”, the device in question essentially opens itself up and transmits a signal to nearby devices within it’s range that it is looking for devices to connect to it; these other devices will pick up on that signal and read off it’s name, what it’s capable of, and what it is (speaker, microphone, TV, etc.)

Bluetooth uses a microwave signal, in the same 2.4 GHz ISM band, as 2.4 GHz WLAN. Where WLAN originally used DSSS spectrum spread (CDM type of coding) and now has moved on to OFDM, Bluetooth uses frequency hopping. 1600 times a second the connection changes between the 79 channels of 1 MHz each. Which makes it rather robust. Since WLAN with OFDM does not occupy the whole band (like DSSS did), Bluetooth can coexist with WLAN in the same room, by avoiding the channels that are allocated by the OFDM scheduler.

I wouldn't call it science. It is good solid R&D work, but it doesn't change our understanding of the world. IEEE have taken the Bluetooth standard(s) under their umbrella in the 802.15 standard series.

This is actually very difficult to answer, as it depends on many varied factors: manufacturing location, quantity, feature set, etc. But i'll be rather general in my answer, and hope that it's close to what you're asking.

If an average US hobbyist were to design and build a basic portable Bluetooth speaker, the costs would, roughly, look something like this:

$15 to $20 - Bluetooth module
$10 to $40 - speakers
$15 to $30 - amplifier, wiring, etc.
$3 to $40 - battery holder or rechargeable battery pack
$5 to $50 - case

As you can see, even a basic design, which is rather simple to wire up, has quite a range of possible costs, depending on the quality of the components. Now, the materials costs go down considerably when mass manufacturing such a device, but, then, there's additional overhead for R&D, marketing, etc.

Companies like Parts Express sell the basic components to build one yourself, including pre-assembled amplifier modules, Bluetooth receiver modules, wire by the foot, battery holders, and speakers. Everything except the case (although they have some generic project cases that might be modifiable to work).

Does this answer your question well enough?

EDIT:
i should mention that a production unit like the Jambox is usually going to have additional functionality than what a DIY system is going to have, because they have the entire system designed to work ideally with each component, and they have often custom programmed the microcontrollers. This is definitely beyond the skillset of a hobbyist.

Also, without having disassembled a Jambox, i cannot answer this with any greater level of accuracy, as it pertains to that brand you have listed.

3D printing is changing manufacturing processes and product design in a number of ways. First, it's making it possible to create highly customized products that can be tailored to individual needs and preferences. Second, it's reducing the amount of waste generated during the manufacturing process. Third, it's making it possible to produce complex products with a high degree of precision. Finally, it's reducing the time and cost required to create prototypes and test new designs. In short, 3D printing is making it possible to create products that were previously difficult or impossible to make using traditional manufacturing methods.

Bluetooth technology is a short-range wireless communications technology to replace the cables connecting electronic devices, allowing a person to have a phone conversation via a headset, use a wireless mouse and synchronize information from a mobile phone to a PC, all using the same core system.
The Bluetooth RF transceiver (or physical layer) operates in the unlicensed ISM band centered at 2.4 gigahertz (the same range of frequencies used by microwaves and Wi-Fi). The core system employs a frequency-hopping transceiver to combat interference and fading.
Bluetooth devices are managed using an RF topology known as a "star topology." A group of devices synchronized in this fashion forms a piconet, which may contain one master and up to seven active slaves, with additional slaves that are not actively participating in the network. (A given device may also be part of one or more piconets, either as a master or as a slave.) In a piconet, the physical radio channel is shared by a group of devices that are synchronized to a common clock and frequency-hopping pattern, with the master device providing the synchronization references.
Let's say the master device is your mobile phone. All of the other devices in your piconet are known as slaves. This could include your headset, GPS receiver, MP3 player, car stereo, and so on.
Devices in a piconet use a specific frequency-hopping pattern, which is algorithmically determined by the master device. The basic hopping pattern is a pseudorandom ordering of the 79 frequencies in the ISM band. The hopping pattern may be adapted to exclude a portion of the frequencies that are used by interfering devices. The adaptive hopping technique improves Bluetooth technology's coexistence with static (nonhopping) ISM systems, such as Wi-Fi networks, when these are located in the vicinity of a piconet.
The physical channel (or the wireless link) is subdivided into time units known as slots. Data is transmitted between Bluetooth-enabled devices in packets that are positioned in these slots. Frequency hopping takes place between the transmission or reception of packets, so the packets that make up one transmission may be sent over different frequencies within the ISM band.
The physical channel is also used as a transport for one or more logical links that support synchronous and asynchronous traffic as well as broadcast traffic. Each type of link has a specific use. For instance, synchronous traffic is used to carry hands-free audio data, while asynchronous traffic may carry other forms of data that can withstand more variability in the timing for delivery, such as printing a file or synchronizing your calendar between your phone and computer.
One of the complexities often associated with wireless technology is the process of connecting wireless devices. Users have become accustomed to the process of connecting wired devices by plugging one end of a cable into one device and the other end into the complementary device.
Bluetooth technology uses the principles of device "inquiry" and "inquiry scan." Scanning devices listen in on known frequencies for devices that are actively inquiring. When an inquiry is received, the scanning device sends a response with the information needed for the inquiring device to determine and display the nature of the device that has recognized its signal.
Let's say you want to wirelessly print a picture from your mobile phone to a nearby printer. In this case, you go to the picture on your phone and select print as an option for sending that picture. The phone would begin searching for devices in the area. The printer (the scanning device) would respond to the inquiry and, as a result, would appear on the phone as an available printing device. By responding, the printer is ready to accept the connection. When you select the Bluetooth wireless printer, the printing process kicks off by establishing connections at successively higher layers of the Bluetooth protocol stack that, in this case, control the printing function.
Like any successful technology, all of this complexity goes on without the user being aware of anything more than the task he or she is trying to complete, like connecting devices and talking hands-free or listening to high-quality stereo music on wireless headphones.
(Courtesy: Scientific American)

I’m not sure if you mean technical reasons or other types of reasons. Either way, as with most things, it was a combination of many reasons. At the core was the desire to get rid of cables. Having cables for mobile phone accessories was a big hassle and having them be wireless was much more convenient. Before Bluetooth, most mobiles had IrDa, but with he line of sight requirement, that was more of a hassle than it was worth.

The technology to build a small, low power, RF radio was developed and became reasonably priced. Once this radio was able to be made in CMOS, it became really cheap. Thus, there were key technology advances as well which made Bluetooth not only possible, but very cost effective.

There were key use cases that people found compelling. In the early days, there were dozens of use cases that people talked about and looked to enable. However, it was really audio, first voice and then stereo, which drive the technology in the early days. This drove adoption into the phones, cars, laptops, etc making the technology appealing to an ever growing set of scenarios.

All these things, as well as others, led to the development and adoption of Bluetooth.

Bluetooth is a wireless technology used to exchange data between devices that supports it. Like Wi-Fi, it doesn’t need cables or wires to connect those devices, just a signal similar to radio-waves to identify others devices in the environment that are capable to “understand” this signal and answer to that.

I’m sure your smartphone is capable to identify and connect to other bluetooth devices around you. By default, it comes with bluetooth device disabled, but if look in your smarthphone settings, you can just put it on and then it will be able to “scan” the environment to discover others bluetooth equipments. And the same way it scans for others, others equipments will also scan the whole environment and discover your cellphone as being responsive for connections.

Bluetooth is a short-range wireless technology operating in the 2.4GHz free ISM band. This is a free band, which means you do not need a special license to operate a product that uses Bluetooth. The range is typically about 10 meters, though there is a variant (called Class 1) that goes up to 100m. It was originally conceived as cable replacement technology (i.e., wherever there is a cable it could potentially be made wireless using Bluetooth)

Its popular use cases have been: handsfree calls, media transfer (sharing photos/contacts/etc), wireless mouse/keyboard, audio streaming, cordless phones, wireless controllers for game stations, in-car calls & audio and others. In the recent times, smart-watches, iBeacons are its newer applications.

Bluetooth has gone through many versions since its genesis in 1998. Its latest (and arguably the most popular) version is Bluetooth Low Energy (LE) - version 4.0 and up.

All major OS/platforms (including mobile) have built-in Bluetooth support. iOS and Android have support for Bluetooth LE.

Bluetooth specifications are open and available here: Specification | Adopted Documents