The OR circuit is called the logical disjunction circuit.
The OR circuit can be thought of as a circuit that outputs when either signal is input.
In same as on the previous page, let's consider an example of turning on a light bulb.
The AND circuit was connected in series, but this OR circuit is connected in parallel.
In other words, if either A or B is ON, the light bulb will be ON.
As shown in the truth table, the output Y will be 1 if 1 is input to either A or B.
The schematic can be expressed by the MIL symbol as shown in the right figure.