A bluetooth device in park/hold mode is part of the piconet but is in a low-power state. These are power saving modes of operation for Bluetooth devices which are connected to a piconet and are used when no data is to be transmitted.The hold mode is used when connecting several piconets or managing a low-power device such as temperature sensor. When the park mode is used t<span>he device is still synchronized to the piconet but does not participate in traffic.</span>
* Main Electron a component- vacuum tube.
* Main memory- Magnetic drums and magnetic tapes.
* Programming language- Machine language.
* Power- Consume a lot of electricity and generate a lot of heat.
* were expensive to operate
