Question

what is the difference between negative feedback amplifier and positive feedback amplifier

Answer 1

The result is a comparator: With negative feedback (the output voltage “fed back” somehow to the inverting input), the circuit tends to prevent itself from driving the output to full saturation. ... Another type of feedback, namely positive feedback, also finds application in op-ampcircuits.

Answer 2

unlike negative feedback where the output voltage is fed back to the inviting (-) input with positive feedback the output voltage is somehow routed back to non inverting(+) .........the inverting input remain disconnected from the feedback loop and is free receive an external voltage