For friends who have not done this kind of engineering, it is too professional not easy to understand, so I will say it is easy to understand.

Choose an active metal which is more negative than the protected metal. This active metal with negative potential is the anode in the electrochemical cell and has priority to corrode and dissolve, so it is called the sacrific anode. Example: If both iron and zinc are put into HCI solution, and the iron and zinc are connected by a metal wire, an electrochemical cell is formed. Iron and zinc act as the cathode and the anode of the cell, respectively. Almost all oxidation occurs at the zinc electrode. The zinc anode subjected to accelerated corrosion is used for cathodic protection of the iron and is called the sacrificial anode. Ladbrokes anticorrosive material is a good choice for projects requiring cathodic protection materials.