What is Bluetooth?
Bluetooth is a wireless technology that allows data exchange between different devices. It is not a piece of wire or plastic that connects your phone and the earpiece but it is the wireless connection between your phone and the earpiece. As you can imagine, Bluetooth is used for wireless communication for a short distance(like from your pocket to your shoulder) without any physical connection.
Technically, Bluetooth technology uses a 2.4 GHz ISM spectrum band (2400 to 2483.5 MHz). It divides the data to be transmitted into packets and transmits each packet on one of 79 designated Bluetooth channels with each channel having a bandwidth of 1 MHz.
Now, you know about Bluetooth but, What Is Bluetooth Low Energy (BLE)?
Bluetooth Low Energy (Bluetooth LE or BLE, formerly known as Bluetooth Smart) is a wireless technology that uses
low-frequency radio waves to transmit wireless data between Bluetooth-enabled devices. It is the smallest, most power-efficient Bluetooth low energy solution. Applications can run on a small battery for four to five years with BLE’s power consumption.
BLE runs on a 2.4 GHz ISM band like Bluetooth. Unlike older Bluetooth, however, it stays in sleep mode all the time unless the connection starts. Its actual connection times are only a few mS, whereas Bluetooth would take nearly 100mS. The reason that the connections are so short is that the data rates are so high at 1 Mb/s. It uses 2 MHz spacing, which accommodates 40 channels.
Apple was the early adopter of BLE on Smartphones with the release of the iPhone 4s in 2011. Today, most Android and iOS devices on the market include BLE communication.
In summary, Bluetooth and Bluetooth Low Energy are used for very different purposes. Bluetooth handles a lot of data but consumes battery life quickly and also the cost is high.
BLE is used for applications that do not require the exchange of large amounts of data and may therefore operate on battery capacity for years at a cheaper price. It all depends on what you are trying to achieve and accomplish.