I've been reading Capital off and on for months and this is a seemingly pretty important difference that I don't understand. Is there a difference between surplus labor and profit, and if so, what is it? Any explanations, links, or chapters in Capital I should check out are appreciated.
My understanding of it:
Surplus value = value workers produce in excess of what they need to live. So if I work 8 hours but only needed to work 3 in order to maintain my current standard of living, my surplus value is 5 hours of labor-time.
Profit = the net earnings of the capitalist through the act of production. The capitalist earns the surplus value produced by workers through exploitation, of course, but not only do they have to pay the workers' wages, they also have to pay for constant capital, which is machinery, equipment, and other things needed for production besides labor.
So profit = surplus value generated - the cost of constant capital.