Hard-to-understand description on calcium chloride (CaCl2) WOW, I'm really getting off topic here explaining about everything!

As I said before, it's a salt that's like an ionic halide.

Molecular formula: CaCl2

CaCl2.2H2O Dihydrate (a chemical compound containing 2 molecules of water. The molecule formula for 'dihydrate' is 2H2O)
CaCl2.4H2O Tetrahydrate (a chemical compound containing 4 molecules of water. The molecule formula for 'tetrahydrate' is 4H2O)
CaCl2.6H2O Hexahydrate (a chemical compound containing 6 molecules of water. The molecule formula for 'hexahydrate' is 6H2O)

Calcium chloride is hygroscopy (has the ability to attract water molecules from the surronding area by asorption and adsorption).

A hydrate is:

"any of a class of compounds containing chemically combined water".

Info from: http://en.wikipedia.org/wiki/Calcium_chloride#Natural_occurrence
http://en.wikipedia.org/wiki/Hydrate
http://en.wikipedia.org/wiki/Tetrahydrate
http://dictionary.reference.com/browse/hydrate
http://dictionary.reference.com/browse/dihydrate
http://dictionary.reference.com/browse/tetrahydrate
http://dictionary.reference.com/browse/hexahydrate