Products of electrolysis on salt water
Chlorine gas
Used for the disinfection for swimming pool water. Also used in industry as a reactant.
Hydrogen
Used as a fuel, especially for rockets.
Sodium hydroxide
The solution left behind can be used to produce wood pulp and bleach.
Pulp
Wood is made into cellulose because NaOH removes everything but the cellulose, which is the main ingredient for pulp and paper.
Bleach
Cl2 (g) + 2NaOH (aq) → NaCl (g) + NaOCl (aq) + H2O (l)
Chlorine + sodium hydroxide → sodium hypochlorite + water