Resting-state functional magnetic resonance imaging (fMRI) is a technique used to study brain function by measuring the spontaneous fluctuations in blood oxygen levels in the brain while a person is at rest. This method is particularly useful for investigating the connectivity and organization of different brain regions in the absence of an explicit task or stimulus. Resting-state fMRI has been used to study various neurological and psychiatric conditions, as well as to better understand the brain's intrinsic network dynamics. It provides valuable information about the functional architecture of the brain and can help researchers and clinicians better understand how different brain regions are interconnected and communicate with each other.