MPI stands for Message passing interface. An implementation of MPI such as MPICH" or OpenMPI is used to create a platform to write parallel programs in a distributed system such as a Linux cluster with distributed memory. Generally the platform built allows programming in C using the MPI standard. So in order to run Parallel programs in this environment in python, we need to make use of a module called MPI4py which means "MPI for Python". This module provides standard functions to do tasks such as get the rank of processors, send and receive messages/ data from various nodes in the clusters.