74LS20 is and no gate chip, 74ls00 is four groups of 2 input terminals with no gate (positive logic). They are basic logic circuits, used to implement and non this logic function.And not gate is a basic logic circuit of digital circuit. Is superimposed with gates and non-gates, with multiple inputs and one output. The and input requires two, and if the input is represented by 0 and 1, then the result of the and operation is the product of these two numbers. If 1 and 1 (with signals at both ends), the output is 0; 1 and 0, the output is 1; 0 and 0, the output is 1.The result of an and not gate is the result of an and operation on two input signals, and then a non-operation on the result of the and operation. To put it simply, with non and non, is first and then non. A basic logic circuit in electrotechnics that is superimposed on a gate and a non-gate, having two inputs and one output.