A cell is the source of energy that generates electric current through chemical reactions.
Explanation of positive :
The reaction will move forward if E (the redox reaction) is positive (spontaneous).
It is possible to generate electricity by a spontaneous process.
One type of electrochemical cell, the galvanic cell (also known as the voltaic cell), transforms the chemical energy of oxidants & reductants into electrical energy.
Electricity can only be created if a redox reaction is spontaneous
For a typical standard galvanic cell (voltaic cell), is positive, meaning that (cell) > 0
(cell), also known as the standard potential difference of a cell or electromotive force (emf), is the highest voltage that a redox cell is capable of producing.