MapReduce

MapReduce is a powerful way of analyzing data that is spread across multiple computers. It works by splitting up the data into smaller pieces, sending it out to the many computers, and then gathering up the results. It is like a giant puzzle, where all the pieces are spread around at the start, then each computer works on a few pieces, and then all the pieces are put back together at the end. You can do things like count how many times a certain keyword appears in a large collection of documents, or combine the data from multiple sources together.