This module is MPI Collective Communication II. Our purpose in this brief module is to introduce you to some of the features of MPI that allow for greater flexibility when using MPI collective operations like scatter or gather. I guess you could say that this module is brought to you by the letter "v". The MPI routines we'll be talking about all end with "v", for example, MPI_Scatterv. You can pretend that the v stands for something like varying or variable. This is because these routines allow you to vary both the size, and the location of the messages that you are using for the communication. We will take MPI_Scatterv and MPI_Gatherv as examples, but you can easily extend these ideas to MPI_Allgatherv and MPI_Alltoallv.