This article reviews recent investigations on the phenomenon of Bose-Einste
in condensation of dilute gases. Since the experimental observation of quan
tum degeneracy in atomic gases, the research activity in the field of coher
ent matter-waves literally exploded. The present topical review aims to giv
e an introduction into the thermodynamics of Bose-Einstein condensation, a
general overview over experimental techniques and investigations, and a the
oretical foundation for the description of bosonic many-body quantum system
s.