I summarize the main observational properties of nova-like (NL) systems in a wide
energy range, from the radio to the X-rays and discuss them in the framework of the theoretical models. The current
classification of NLs and the defining characteristics of each sub-type are discussed. I
also present a statistical overview of a number of the known NL systems of different sub-types and
compare their orbital period distribution with that of dwarf novae and novae.