I will try to explain it. If you are not familiar with chemistry this might indeed be hard to understand.
Fluorine (F) is the atom of fluorine by itself. Apperantly it can also form bonds with itself (F2). This stuff is extremely reactive and dangerous. F and F2 rapidly react with other substances such as water. Water consist out of two hydrogen atoms and an oxygen atom. Hydrogen is positively charged and fluorine is negatively charged. The product of the reaction is fluoride or in this case FH (consists out of one atom of fluorine and one atom of hydrogen). You can substitute the hydrogen for other possitively charged atoms such as Natrium (Na). The product is called fluoride also. Fluoride can thus consist of fluoride bonded to many different positely charged atoms.
ive seen the effect of flouridation first hand my comrades. my cousin ingested a dangerouse amount of flouride when he was around 2 years old. since then the doctor has classified him with mild torrets sydrom. "pardon the spelling". He is a normally functioning person but the fact still remains that when he ingested floride toothpast ion a large amount he gained a mental dysfunction. secondly ever notice why the european countries with no flouride in their water have higher life expectancys?