The brain and spinal cord are covered and protected by three layers of tissue called Meninges, named:
Arachnoid Mater
The Arachnoid mater is a thinelastic tissue covering the entire brain.
Dura Mater
The Dura Mater is a strong, thick membrane that closely lines the inside of the skull. The dura creates little folds or compartments - some separating the right and left hemispheres of the brain and the cerebrum from the cerebellum.
Pia Mater
The Pia Mater hugs the surface of the brain following its folds and grooves and has many blood vessels that reach deep into the brain. the space between the Arachnoid and Pia is where the Cerebrospinal Fluid bathes and cushions the brain.