Big Data represents a collection of data sets so large and complex that it becomes difficult to process using on-hand database management tool.
It is also unstructured, meaning that it is not tabulated, correlated, etc. (e.g. it does not have a pre-defined data model or is not organized in a pre-defined manner).
Big Data technologies enable organizations to handle huge datasets and generate information/insights from them with minimal delay time (sometimes in real-time).
Leading companies in Big Data are the already making great strides and will surely represent the forbearers of many great solutions yet to come