  Since the quark-gluon plasma (QGP) reveals some obvious similarities to the
well-known electromagnetic plasma (EMP), an accumulated knowledge on EMP can be
used in the QGP studies. After discussing similarities and differences of the
two systems, we present theoretical tools which are used to describe the
plasmas. The tools include: kinetic theory, hydrodynamic approach and
diagrammatic perturbative methods. We consider collective phenomena in the
plasma with a particular emphasis on instabilities which crucially influence
temporal evolution of the system. Finally, properties of strongly coupled
plasma are discussed.
