helps us for typing letters, numbers and symbols etc.
Types in java are divided into two categories. the primitive types are boolean, byte, char, short, not, long, float, and double. all other types are REFERENCE types
802.11 is a Wi-Fi standard, not a frequency, both of those operate at 2.4 GHz. Bluetooth operates at frequencies between 2402 and 2480 MHz, or 2400 and 2483.5 MHz.
