  The concept of Late Veneer has been introduced by the geochemical community
to explain the abundance of highly siderophile elements in the Earth's mantle
and their chondritic proportions relative to each other. However, in the
complex scenario of Earth accretion, involving both planetesimal bombardment
and giant impacts from chondritic and differentiated projectiles, it is not
obvious what the "Late Veneer" actually corresponds to. In fact, the process of
differentiation of the Earth was probably intermittent and there was presumably
no well-defined transition between an earlier phase where all metal sunk into
the core and a later phase in which the core was a closed entity separated from
the mantle. In addition, the modellers of Earth accretion have introduced the
concept of "Late Accretion", which refers to the material accreted by our
planet after the Moon-forming event. Characterising Late Veneer, Late Accretion
and the relationship between the two is the major goal of this chapter.
