Another thing to be aware of with accelerometers and gyro's is the measurement
range, for instance accelerometer might have +/-2g range or +/-8g, and gyros
vary with maximum rotation rate.
WiFi is a full networking standard, if a module doesn't mention WiFi it won't be
WiFi, since this is a major selling point. WiFi uses advanced spread-spectrum
technology, simple 2.4GHz transceiver modules are typically single carrier FM
(often with configurable parameters) and ZigBee modules use the IEEE 802.15.4
standard.
Smartphones tend to have BT and WiFi.