Commodity
As defined in his book by Marx, a commodity is any "object outside us, a thing that by its properties satisfies human wants of some sort or the other".
Use value
The ability of a commodity to satisfy a given human want. It comprises of one of the two-fold values of a commodity.
Exchange value
Exchange value is the other part of the two-fold value of a commodity. It is the value that a commodity possesses when offered in exchange of another commodity.
Concrete labour
Concrete labour is the type of labor that produces either a use value, or an exchange value
Abstract labour
The type of labour that creates an exchange value. The exchange value is dependent on the quality of abstract labor.
Constant capital
It is that part of the capital that comprises of the means of production necessary to produce a commodity. It includes the machinery, and thus does not undergo any variations.
Variable capital
It is that part of capital comprising of labor power, and thus undergoes variations in the production process.
Necessary labor
The labor required to produce the commodity.
Surplus labor
The excess labor that is not required to produce the commodity, but may be added to speed up the production process.
Labor power
As stated by Marx, labor power is the "aggregate of those mental and physical capabilities existing in the physical form, the living personality, of a human being, capabilities which he sets in motion whenever he produces a use-value of any kind." Thus, labour power is the human effort that is invested to make a product.