Grant me a "crabby old guy" rant on big data. I continually hear people in our industry using the term big data as a product-category name -- and confusing everyone about the business value of big data solutions. Moreover, too many people now seem to think that Hadoop is big data, when Hadoop is just one of the several big-data solutions available -- and Hadoop isn't good for many big data scenarios.
Big data is a label for the trend toward processing dynamic (and therefore voluminous) data using in-memory architectures. This trend is being played out in 8 major scenarios that I can find. In each case, enterprises are struggling to understand how the various big data solutions will help generate revenue and profits, manage expenses, and service customers and citizens.