  We present some recent highlights and prospects for the study of hot
astrophysical plasmas. Hot plasmas can be studied primarily through their X-ray
emission and absorption. Most astrophysical objects, from solar system objects
to the largest scale structures of the Universe, contain hot gas. In general we
can distinguish collisionally ionised gas and photoionised gas. We introduce
several examples of both classes and show where the frontiers of this research
in astrophysics can be found. We put this also in the context of the current
and future generation of X-ray spectroscopy satellites. The data coming from
these missions challenge the models that we have for the calculation of the
X-ray spectra.
