Here we're going to say that an electrochemical cell is what we call a cell potential. Now this cell potential will be under standard conditions or non-standard conditions. Cell potential is Ecell. If it's under standard conditions we use not a little circle here or zero. If it's non-standard conditions, it doesn't have that little knot or circle.
Now cell potential is just the difference in potential energies as electrons travel between the half cells. Remember 1/2 cell deals with oxidation where we're losing electrons. The other one deals with reduction when we're gaining electrons. The traveling of the electrons is what creates potentially electricity. Now here this will be measured in volts. So volts here will be using the variable V.
Now recall standard conditions are 25°C, one molar, one atmosphere and pH equal to seven. Under these conditions we'd use this cell potential. If we aren't following these standard conditions then we're talking about non-standard cell potential. Now there are two types of electrochemical cells, one that produces electricity so makes it and one that consumes electricity so uses it up.
These two types of electrochemical cells have names given to them, so one is called a galvanic cell. This one has a cell potential that is positive, whether that be standard or non-standard, meaning electricity is produced. So if we have an electrochemical cell that is positive in terms of its cell potential, it represents a galvanic cell. Galvanic cells produce electricity.
An electrolytic cell, by contrast, would have a cell potential that is negative. Because of this, it doesn't produce electricity. It consumes or uses it up. So just remember we have standard cell potential and non-standard cell potential and then we have two types of electrochemical cells based on the idea of either making or producing electricity. So those will be our galvanic cells or consuming or using up electricity. Those would be our electrolytic cells.