The OR Gate has 2 inputs and 1 output. It will output power if it receives power from at least one of its input sides. The image on the right shows the 2 inputs that are linked together. Similar gates are the XOR Gate, the NOR Gate and the XNOR Gate.
An OR Gate is used for circuits where multiple power sources can power the same thing, such as 2 buttons placed around a house, that cause a piston to seal the entrance or open a door when pressed. When using buttons or pressure plates however, an equal solution is an Alloy Wire instead. The main difference when using an OR Gate is that multiple signals will only connect to the Output and don't affect any other outcome. This might be useful when more than one gate or cell is connected in the same circuit.
0's represent an inactive signal. 1's represent an active signal.
Note that the outcome is equally to the Output of the OR Gate.