Scalp is the soft tissue layer covering the bony vault over the brain.

Scalp is the soft tissue layer covering the bony vault over the brain. It is usually described as having five layers, which can conveniently be remembered as a mnemonic:

S: The skin on the head from which head hair grows. It contains numerous sabaeceous glands and hair follicles
C: Connective tissue. A thin layer of fat and fibrous tissue lies beneath the skin.
A: The aponeurosis called epicranial aponeurosis (or galea aponeurotica) is the next layer. It is a tough layer of dense fibrous tissue which runs from the frontalis muscle anteriorly to the occipitalis posteriorly.
L: The loose areolar connective tissue layer provides an easy plane of separation between the upper three layers and the pericranium. I
P: The pericranium is the periosteum of the skull bones and provides nutrition to the bone and the capacity for repair. 

Know more: http://en.wikipedia.org/wiki/Scalp