Bluetooth Keyboards can be connected to an iPad/iPhone in the Settings App. Bluetooth can be described as invisible cord that connects one thing to another, called pairing.
From the left hand menu, choose Bluetooth. Drag the switch to the right to turn Bluetooth on.
Once Bluetooth is enabled, the iPad/iPhone should begin to search for Bluetooth devices that are within the vicinity of the iPad/iPhone, indicated by a spinning wheel (red box). Choose the device that you want to connect to by tapping it once.
Once selected, a spinning wheel should appear beside the selected device to indicate that it is attempting to pair with the iPad/iPhone. The device will either pair automatically (proceed to next step) or an instruction will be given on the iPad/iPhone screen. In the picture to the left of this instruction, the iPad has provided a PIN to connect to a keyboard. Type the PIN on the keyboard you wish to pair and press Enter.
If the Bluetooth device has connected properly, it will be listed as Connected on the list of Bluetooth devices.
From the list of Bluetooth devices, tap the blue "i" beside Connected. You can then choose to Disconnect or Forget This Device. If there are connection issues, try tapping Forget This Device and start the connection process from the beginning.