Describe what is the basics of Cathodic protection?

Cathodic Protection (CP) is a technique used to control the corrosion of a metal surface by making it the cathode of an electrochemical cell. A simple method of protection connects protected metal to a more easily corroded "sacrificial metal" to act as the anode.

Cathodic protection is one method used to prevent corrosion in pipelines.

is a naturally occurring phenomenon commonly defined as the deterioration of a substance (usually a metal) or its properties because of a reaction with its environment. The tendency of a metal to corrode depends on the grain structure of the metal, its composition as formed during alloying, and the temperature or deformation of a single metal surface developed during fabrication. Corrosion occurs as a result of an electrochemical reaction driven by a potential difference between two electrodes, an anode and a cathode, connected by an electronic path and immersed in the same electrolyte. In the case of uniform corrosion, a multitude of microscopic anodic and cathodic sites exist on the surface of the metal structure.