  The contribution of this short note, contains the following two parts: in the
first part, we are able to show that the federate learning (FL) procedure
presented by Kairouz et al. \cite{Kairouz1901}, is a random processing. Namely,
an $m$-ary functionality for the FL procedure can be defined in the context of
multi-party computation (MPC); Furthermore, an instance of FL protocol along
Kairouz et al.'s definition can be viewed as an implementation of the defined
$m$-ary functionality. As such, an instance of FL procedure is also an instance
of MPC protocol. In short, FL is a subset of MPC.
  To privately computing the defined FL (m-ary) functionality, various
techniques such as homomorphic encryption (HE), secure multi-party computation
(SMPC) and differential privacy (DP) have been deployed. In the second part, we
are able to show that if the underlying FL instance privately computes the
defined $m$-ary functionality in the simulation-based framework, then the
simulation-based FL solution is also an instance of SMPC. Consequently, SFL is
a subset of SMPC.
