Resting state network (RSN) refers to the patterns of synchronized brain activity that occur when a person is at rest and not engaged in any specific tasks. These networks are typically identified using functional magnetic resonance imaging (fMRI) or electroencephalography (EEG) techniques, which measure brain activity by detecting changes in blood flow or electrical signals. There are several key resting state networks that have been identified, including the default mode network (DMN), which is associated with self-referential and mind-wandering thoughts, and the central executive network (CEN), which is involved in goal-directed cognitive tasks. Studies of resting state networks have provided valuable insights into the organization of the human brain and its functional connectivity. Researchers have found that disruptions in RSNs are associated with various neurological and psychiatric disorders, such as Alzheimer's disease, schizophrenia, and depression. Overall, the study of resting state networks has contributed to a better understanding of the brain's intrinsic activity and has important implications for both basic neuroscience research and clinical applications.