with an NPN BJT (bipolar junction transistor) and two resistors you can create a Not gate.
The XNOR gate is an inverted XOR gate. The out put is only true when either all the inputs are false, or all the inputs are true. It is effectively an XOR gate in series with a NOT gate.
A NOR gate simply produces a true output only when all of the inputs are false. It is effectively just an OR gate in series with a NOT gate.
Exclusive OR (XOR) gates operate on the same logic as an OR gate excluding one difference. If more than one of the inputs is true, then the output will be false.
In order for the output to be true, only one of the inputs can be true.
A NAND gate is an AND gate whose output has been inverted. This effectively means that unless all inputs are true, the output will be true.
A NOT gate (Inverter), is a single input logic gate. The output is simply opposite to that of the input.
You can simply create a NOT gate by using an NPN transistor and two resistors as shown here: ‘https://thelectronicsblog.wordpress.com/2015/11/29/not-gate-using-a-transistor’
An OR gate only requires one inputs to be true for the output to be true. All inputs need to be false for the output to be false.
An AND gate requires all inputs to be true for the output to be true. Any other combination results in the output being false.