In a negative feedback configuration of an operational amplifier, how does the input and output relationship in a closed-loop system differ from that in an open-loop system in terms of frequency response?

In an open‑loop op‑amp the gain is very high at low frequencies but it falls off steeply once the internal pole is reached, so the input‑output relationship changes rapidly with frequency. When negative feedback is applied, the closed‑loop gain is set to a finite value and the op‑amp’s bandwidth is effectively stretched; the gain stays nearly constant up to a new, higher cutoff frequency. This happens because the feedback forces the output to follow the input more closely, reducing the impact of the internal pole. For example, an op‑amp with a 10⁵ open‑loop gain that rolls off at 10 Hz can be set to a closed‑loop gain of 10, giving a flat response up to about 100 kHz. Thus, the closed‑loop system has a lower, more stable gain and a much wider usable frequency range than the open‑loop configuration.