  Nearly all intragroup (IGL) and intracluster light (ICL) comes from stars
that are not bound to any single galaxy but were formed in galaxies and later
unbound from them. In this review we focus on the physical properties - phase
space properties, metallicity and age distribution - of the ICL and IGL
components of the groups and clusters in the local universe, within 100 Mpc
distance. Kinematic information on these very low surface brightness structures
mostly comes from discrete tracers such as planetary nebulae and globular
clusters, showing highly unrelaxed velocity distributions. Cosmological
hydrodynamical simulations provide key predictions for the dynamical state of
IGL and ICL and find that most IC stars are dissolved from galaxies that
subsequently merge with the central galaxy. The increase of the measured
velocity dispersion with radius in the outer halos of bright galaxies is a
physical feature that makes it possible to identify IGL and ICL components. In
the local groups and clusters, IGL and ICL are located in the dense regions of
these structures. Their light fractions relative to the total luminosity of the
satellite galaxies in a given group or cluster are between a few to ten
percent, significantly lower than the average values in more evolved, more
distant clusters. IGL and ICL in the Leo I and M49 groups, and the Virgo
cluster core around M87, has been found to arise from mostly old (>~10 Gyr)
metal-poor ([Fe/H]<-1.0) stars of low-mass progenitor galaxies. New imaging
facilities such as LSST, Euclid, and the `big eyes' on the sky - ELT and JWST
with their advanced instrumentation-promise to greatly increase our knowledge
of the progenitors of the IGL and ICL stars, their ages, metal content, masses
and evolution, thereby increasing our understanding of this enigmatic
component.
