gyri
The answer is quite simple. The fine folds of the brain are called "folia".
The surface of the brain is not regarded as being smooth. In a normal human brain, there are definite "folds" evident, and we often use the term convoluted to describe the outward appearance of the brain. Use the link below to see some images that will help lock in the idea.
Surface area.
Gyrus
Gyri are the folds in the brain that store memories. These are located on the cerebral cortex, along with the sulci.
gyri, its "elevated ridges"
The folds on the surface of the brain are called gyri.
helps increase the brain's surface area
The folds in the brain that store memories are called the hippocampus. The hippocampus is a part of the brain that is involved in the formation, organization, and storage of memories. It plays a crucial role in both short-term and long-term memory.
They are called sulci (plural of sulcus).
It is not sufficient to describe memory, and its counterpart, learning, as solely dependent on specific brain regions such as the folds of the brain. Brain areas involved in the neuroanatomy of memory such as the hippocampus, the amygdala, the striatum, or the mammillary bodies are thought to be involved in specific types of memory. Memory is actually stored in the spaces between the neurons and not in or on certain folds.
The brain is covered in ridges (gyri) ans grooves (sulci).