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Some of the terms that you must understand in this tutorial are:

• MPI Communicator:

  Allows a group of processes to communicate with each other.

  Following are the MPI routines for initializing MPI and the communicator and finalizing a session with MPI:

      C               Fortran          Description
      --              -------          -----------
      MPI_Init        MPI_INIT         Initialize MPI (MPI_COMM_WORLD usually)
  
      MPI_Comm_size   MPI_COMM_SIZE    Define how many processes are contained 
                                       in the communicator
  
      MPI_Comm_rank   MPI_COMM_RANK    Define the process ID number within 
                                       the communicator (from 0 to n-1)
  
      MPI_Finalize    MPI_FINALIZE     Exiting MPI
  

• • Collective:   MPI defines this to mean all processes of the communicator must participate in the right order.

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