  In this paper a discussion of kinematics and physics of the Broad Line Region
(BLR) is given. The possible physical conditions in the BLR and problems in
determination of the physical parameters (electron temperature and density) are
considered. Moreover, one analyses the geometry of the BLR and the probability
that (at least) a fraction of the radiation in the Broad Emission Lines (BELs)
originates from a relativistic accretion disk.
