The "brain" as we tend to refer to it is a structure of densely packed nerve cells (neurons) called the cerebral cortex. On a broad level, the cerebral cortex is divided into four main areas (termed lobes). The frontal lobe is critical for motor execution and eye movement. The temporal lobe is critical for auditory processing and visual and language memory. The parietal lobe is critical for sensory processing. The occipital lobe is critical for vision and visual processing.
The frontal lobe is the largest area of the brain. It is primarily responsible for the planning and execution of actions as well as inhibition.
The primary motor cortex controls the majority of movement. The left side of the brain controls movement for the right side of the body, and vice-versa. The main crossing location of these motor fibers occurs in the brainstem.
The medial prefrontal cortex, orbitofrontal area, and the medial frontal area are responsible for motivation and social information processing and regulating emotions, behavior, and personality.
The frontal lobe also contains Broca's area (expressive language area) which is controls speech and the frontal eye fields that help direct eye movements.
The temporal lobe contains critical areas that process and retain visual and auditory information. The primary auditory cortex is contained here, as is Wernicke's area which is critical for language comprehension. The temporal lobe is also responsible for the ventral or "what" pathway of visual processing.
A large portion of the parietal lobe is dedicated to sensation. The primary somatosensory cortex receives sensory input from the opposite side of the body. The parietal lobe also contains areas responsible for the dorsal or "where" pathway of visual processing and spatial orientation.
The occipital lobe is dedicated to vision. It receives information from the lateral geniculate nucleus of the thalamus, and aids in the processing of visual information. The primary visual cortex is contained in the occipital lobe.
The insula is a small area of the brain that plays a role in basic emotions, desires and addictions, emotion, pain, and bodily awareness. The insula is a less well-understood portion of the cerebral cortex.
The limbic system is composed of the hypothalamus, amygdala, thalamus, basal ganglia, and hippocampus. This is the "emotional" brain and contributes to memory formation and storage, as well as regulation of hormones.
Sources: Neuroanatomy, Cerebral Cortex: https://www.ncbi.nlm.nih.gov/books/NBK537247/
Know Your Brain: https://www.neuroscientificallychallenged.com/know-your-brain