  We provide a characterization of energy in the form of exchanged heat and
work between two interacting constituents of a closed, bipartite, correlated
quantum system. By defining a binding energy we derive a consistent quantum
formulation of the first law of thermodynamics, in which the role of
correlations becomes evident, and this formulation reduces to the standard
classical picture in relevant systems. We next discuss the emergence of the
second law of thermodynamics under certain---but fairly general---conditions
such as the Markovian assumption. We illustrate the role of correlations and
interactions in thermodynamics through two examples.
