A disinfectant is any substance that causes the destruction (kills or eliminates) pathogenic and other kinds of microorganisms (such as Bacteria, viruses or fungi. While there are many reliable disinfectants on the market, no one is perfect for killing all microbes or eliminating spores.
Disinfection should NEVER be confused with sterilization! Disinfection is generally used on hard surfaces (counter tops, etc.) but is NOT sufficient for jewelry or tools which come in contact (including indirect contact) with the body.