  In this paper we consider composition operator $C_{\varphi} generated by
nonsingular measurable transformation $T$ and multiplication operator $M_u$
generated by measurable function $u$ between two different Orlicz spaces, then
we investigate boundedness, compactness and essential norm of multiplication
and composition operators in term of properties of the mapping $\varphi$, the
function $u$ and the measure space $(X, \Sigma, \mu)$.
