The blog discusses a method for multiplying a large square matrix by a vector using MPI with a block-column distribution strategy. It describes how Process 0 distributes matrix columns to different processes, which calculate local products and then combine results using MPI Reduce scatter. An understanding of vector multiplication is emphasized, explaining how vectors are represented in C, including examples of single and square vectors. The process of matrix-vector multiplication is detailed with a C code snippet, demonstrating each multiplication step and the final result. The blog prepares readers for implementing parallel computations in MPI, enhancing efficiency.