  This paper investigates evolution of cosmic structures in different
environments. For this purpose the quasispherical Szekeres model is employed.
The Szekeres model is an exact solution of the Einstein field equations within
which it is possible to describe more than one structure. In this way
investigations of the evolution of the cosmic structures presented here can be
freed from such assumptions as small value of the density contrast. Also,
studying the evolution of two or three structures within one framework enables
us to follow the interaction between these structures and their impact on the
evolution. Main findings include a conclusion that small voids surrounded by
large overdensities evolve slower than large, isolated voids do. On the other
hand, large voids enhance the evolution of adjacent galaxy superclusters which
evolve much faster than isolated superclusters
