Brain regions are specific areas of the brain that have distinct functions and are responsible for various cognitive processes and behaviors. These regions can be identified through neuroimaging techniques such as fMRI and PET scans. Some common brain regions include the frontal lobe, which is involved in decision-making and problem-solving, the hippocampus, which is essential for memory formation and retrieval, and the amygdala, which plays a crucial role in emotional processing and responses. Studying brain regions can help researchers better understand how the brain functions and how different areas work together to produce complex behaviors and thoughts.