  We demonstrate that the generalization of the relativistic Toda chain (RTC)
is a special reduction of two-dimensional Toda Lattice hierarchy (2DTL). We
also show that the RTC is gauge equivalent to the discrete AKNS hierarchy and
the unitary matrix model. Relativistic Toda molecule hierarchy is also
considered, along with the forced RTC. The simple approach to the discrete RTC
hierarchy based on Darboux-B\"acklund transformation is proposed.
