Simply we can say that a gate will have two interpretation depending on positive and negative logics. Those can be represented by positive logic input and negative logic inputs.

Example,

1 - Higher input

0 - Lower input

And in electronics, we use two level of voltages 0V and +SV dc voltage. We can say 0 for low voltage and 1 for high voltage (+SV dc). This system of digital logic is called positive logic.

But the system of digital logic where binary 0 represents higher voltage and binary 1 represents low voltage is called negative logic.

Example,

1 - Higher input

0 - Lower input

And in electronics, we use two level of voltages 0V and +SV dc voltage. We can say 0 for low voltage and 1 for high voltage (+SV dc). This system of digital logic is called positive logic.

But the system of digital logic where binary 0 represents higher voltage and binary 1 represents low voltage is called negative logic.