Step 1 of 7: Definition

MPI stands for Message Passing Interface. The goal of MPI, simply stated, is to develop a widely used standard for writing message-passing programs. As such, the interface attempts to establish a practical, portable, efficient, and flexible standard for message passing. In designing MPI, the MPI Forum sought to make use of the most attractive features of a number of existing message passing systems, rather than just selecting one of them and adopting it as the standard. 

The main advantages of establishing a message-passing standard are portability and ease-of-use. In a distributed memory communication environment, in which the higher level routines and/or abstractions are build upon lower level message passing routines, the benefits of standardization are particularly apparent. Furthermore, the definition of a message passing standard provides vendors with a clearly defined base set of routines that they can implement efficiently, or in some cases provide hardware support for, thereby enhancing scalability.