The oxidation reduction reactions are called redox reaction. These reactions are take place by gaining or losing the electrons and oxidation state of elements are changed.
Oxidation:
Oxidation involve the removal of electrons and oxidation state of atom of an element is increased.
Reduction:
Reduction involve the gain of electron and oxidation number is decreased.
In given reaction fluorine gas gain two electron and form fluoride ions.
F₂(g) + 2e⁻ → 2F⁻(aq)
The given reaction is reduction because oxidation state is decreased from zero to -1.
Because water conducts electricity, so if an electrical current were to meet the water while you're in there taking a bath, you would essentially be surrounded by a huge conductor.