What type of amplifier applies the input signal to the inverting input?

The inverting amplifier is characterized by applying the input signal to its inverting input terminal. This configuration is distinct because it produces an output that is 180 degrees out of phase with the input; meaning it inverts the signal. In addition to phase inversion, the output voltage is also proportional to the input voltage based on the feedback resistors used in the circuit, following the formula Vout = - (R2/R1) * Vin, where R1 is the resistor connected to the input signal, and R2 is the feedback resistor. This relationship allows for controlling the gain of the amplifier.

In contrast, the non-inverting amplifier applies the input signal to the non-inverting input and provides an output that is in phase with the input. The summing amplifier is designed to combine multiple input signals into one output, applying each signal to the inverting input, but it does not solely apply a single signal at this terminal as an inverting amplifier does. Lastly, a buffer amplifier doesn't amplify the signal but instead provides isolation and unity gain, applying the input to the non-inverting terminal.