Explanation:
its too old question bro I can't answer just for points
Answer:
i not know mainframe computer there is many use of computer
Answer:It rearranges the files on a hard drive to get quicker access to them.
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.