Interlaced refresh rate is a technique for doubling the perceived frame rate of a video display without consuming extra bandwidth. It is used in broadcast television to reduce the amount of bandwidth needed for each frame but still maintain a high refresh rate. Interlaced displays change every other row with each screen refresh, which means that only half of the pixels get refreshed on each cycle. This process happens so quickly, typically 1/75 of a second in a 75 Hz display, that it results in smoother motion and reduces flicker.

In contrast, progressive scan means the whole screen is refreshed every single frame, which results in a higher spatial resolution for low-motion scenes. Progressive is typically the superior format for most use cases, as interlaced videos develop visual noise when the two frames dont match up thats distracting.

It is worth noting that interlaced refresh rate is not the same as variable refresh rate, which synchronizes the monitors refresh rate with a games frame rate.