Negative Feedback: When a portion of the output signal is fed back to the input in such a way that it is out of phase with the input signal and opposes it.

• Reduces system gain, improves stability, and increases accuracy.
• Commonly used in control systems, amplifiers, and oscillators to stabilise performance.

Positive Feedback: When a portion of the output signal is fed back to the input in such a way that it is in phase with the input signal and adds to it.

• Increases system gain, but can lead to instability and oscillations.
• Used in circuits like regenerative amplifiers and oscillators.

Characteristics of negative feedback:

• Negative feedback promotes stability by correcting deviations, helping the system settle to a stable state or equilibrium.
• The output impedance of the system becomes very low, making the closed-loop amplification nearly independent of the load.
• The system's gain remains stable and less sensitive to variations in component values or external disturbances.
• Negative feedback extends the range of frequencies over which the system can operate effectively.
• It ensures that only the right amount of correction is applied, preventing overcompensation.
• The system becomes more precise and reliable, with reduced distortion and noise.
• The response time to input changes is improved, leading to better dynamic performance.