In the paper we consider boundary -- value problems with rapidly alternating
type of boundary conditions, including problems in domains with perforated
boundaries. We present the classification of homogenized (limit) problems
depending on the ratio of small parameters, which characterize the diameter of
parts of the boundary with different types of boundary conditions or on the
ratio of small parameters, which characterize the diameter and the distance
between holes. Also we studied the analogue of the Helmholtz resonator for
domains with perforated boundary.