NOT Gate (Inverter): A NOT gate has one input and one output. It simply reverses the input signal—when the input is ON (1), the output is OFF (0), and when the input is OFF (0), the output is ON (1). It is used to understand the concept of inversion in digital electronics. AND Gate: An AND gate has two inputs and one output. The output turns ON only when both inputs are ON (1,1). If any one input is OFF, the output remains OFF. It is commonly used in logic-based decision systems and control circuits. OR Gate: An OR gate also has two inputs and one output. The output turns ON when any one or both inputs are ON. The output is OFF only when both inputs are OFF. It helps students understand parallel decision-making logic. Together, NOT, AND, and OR gates form the foundation of digital electronics, making them essential for Class 12 practicals, school science projects, STEM learning, and competitive exam preparation—just like basic concepts in maths before advanced chapters, a familiar approach in Indian classrooms