Where is cerebrospinal fluid present? Please explain.

Cerebrospinal fluid (CSF) is a clear, colorless body fluid found in the brain and spine. The CSF occupies the subarachnoid space (between the arachnoid mater and the pia mater) and the ventricular system around and inside the brain and spinal cord. It constitutes the content of the ventricles, cisterns, and sulci of the brain, as well as the central canal of the spinal cord.