The process is fairly simple: Salt is composed of two elements: Sodium and Chloride. By separating those elements, Chloride is released into the water and sanitizes it.
After the sanitization process, the Sodium and Chloride naturally tend to join back together into salt. Thus, no salt is lost during the process. The only thing that is consumed is the electricity that the salt chlorinator uses to separate the elements.
The salt chlorinator is composed two things: a Cell and a Control box. The cell is a tube in which the water goes through. This tube has metal plates inside it. The Control box is a mini computer that monitors and control the chlorine generation process: It monitors the salt level in the pool and it send electrical current into the cell's metal plate in order to activate the salt separation process.
Of course, this is a very simple explanation of a fairly complex chemical process, but this was the intent of this article: Explain in simple words how swimming pool salt chlorinator works!
You may wonder if it is ok to use normal salt in salt chlorinated pool. You can read
this article to find the answer.