Bleach is a solution of sodium (or calcium depending on your location) hypochlorite.
Sodium hypochlorite is NaOCl.
Calcium Hypochlorite is Ca(OCl)2.
In either case, the active compound is the hypochlorite ion ClO-.
Bleach also has some sodium hydroxide in there to keep the pH at an elevated level since sodium hypochlorite is formed by the action of chlorine gas on some sodium hydroxide. At low pH, the equillibrium is in favor of chlorine gas and NaOH. At high pH, the equillibrium rests on the side of sodium hydroxide.
So in a typical bottle of Chlorine Bleach, you have mostly water with about 5% on average sodium hypochlorite, some sodium chloride, and some sodium hydroxide.