  The recent high angular resolution observations have shown that the
transition between a globally symmetrical giant and a source surrounded by a
spatially complex environment occurs relatively early, as soon as the external
layers of the stars are not tightly bound to the core of the star anymore. In
this review, the emphasis will be put on the delineating the differences
between the torus and disk classification through the presentation of many
examples of near-IR and mid-IR high angular resolution observations. These
examples cover the disks discovered in the core of some bipolar nebulae,
post-AGB disks, the dusty environment around born-again stars and recent novae,
and also the disks encountered around more massive evolved sources. We discuss
the broad range of circumstances and time scales for which bipolar nebulae with
disks are observed.
