  More luminous than classical novae, but less luminous than Supernovae, lies
the exotic stellar eruptions known as Intermediate luminosity optical
transients (ILOTs). They are divided into a number of sub-groups depending on
the erupting progenitor and the properties of the eruption. A large part of the
ILOTs is positioned on the slanted Optical Transient Stripe (OTS) in the
Energy-Time Diagram (ETD) that shows their total energy vs. duration of their
eruption. We describe the different kinds of ILOTs that populate the OTS and
other parts of the ETD. The high energy part of the OTS hosts the supernova
impostors -- giant eruption (GE) of very massive stars. We show results of 3D
hydrodynamical simulations of GEs that expose the mechanism behind these GEs,
and present new models for recent ILOTs. We discuss the connection between
different kinds of ILOTs, and suggest that they have a common energy source --
gravitational energy released by mass transfer. We emphasize similarities
between Planetary Nebulae (PN) and ILOTs, and suggest that some PNe were formed
in an ILOT event. Therefore, simulations used for GEs can be adapted for PNe,
and used for learning about the influence of the ILOT events on the the central
star of the planetary nebula.
