If Bluetooth is available on the smartphone or not. Having bluetooth in your phone enables it to make data transfers wirelessly to another bluetooth supported devices, which includes file transfers, wireless audio etc.
Bluetooth version present on the smartphone. Bluetooth versions indicate the generation and with every generation the bluetooth connection becomes better in various ways. The bluetooth versions started with Bluetooth 1.x then came Bluetooth 2.x and the nomenclature goes similarly for later versions.
Wireless data encryption algorithms for audio through smartphones. It encodes and decodes digital audio data into a specific format. Ideally, it transmits a high-fidelity signal at the minimum specified bit-rate.
Wireless pairing technology by bringing two supported phones with 4cms of each other. NFC is used for social networking, for sharing contacts, photos, videos or files. NFC-enabled devices can act as electronic identity documents and keycards.
USB connector type
The data/power input/output port on the smartphone. The USB connectors include Type A, type B, Micro USB, Mini USB, and USB-C.
Audio connector type
The audio input/output port on the smartphone. The audio connectors range for analog 2.5mm, 3.5mm ports to various digital USB ports.
The ability to connect to the internet wirelessly. Wifi let's you connect various devices to the same network and get access to internet with a wire-free experience.
TV-Out, Computer sync, OTA sync
Ability to transmit compressed or uncompressed audio/video data through wired connection to a supported device like a display controller, computer monitor, video projector, or a digital television.