  We elaborate on various aspects of the conformal field theory of the
symmetric orbifold. We collect various results that have appeared in the
literature, and we present a coherent picture of the operator content of this
CFT, relying on the orbifold extension of the Virasoro algebra. We then focus
on the large $N$-limit of this theory, discuss the OPE of two twist operators,
and find various selection rules. We review how to calculate four-point
functions of twist operators, and we write down the most general four-point
function in the covering space for large $N$. We show that it depends on some
functions that obey a set of algebraic equations, that resemble the scattering
equations. Finally, we provide a recipe on how to calculate correlation
functions with insertions of the orbifold Virasoro generators.
