"Business Intelligence (BI) is a set of methods and tools that are used by organizations for accessing and exploring data from diverse source systems to better understand how the business is performing."
BI (Business Intelligence) is a term commonly associated with DW (Data Warehousing). In fact, many of the tool vendors position their products as business intelligence software rather than data warehousing software. There are other occasions where the two terms are used interchangeably.
BI is the ability for an organisation to take all its capabilities and convert them into knowledge, ultimately, getting the right information to the right people, at the right time, via the right channel. This produces large amounts of information which can lead to the development of new opportunities for the organisation. When these opportunities have been identified and a strategy has been effectively implemented, they can provide an organisation with a competitive advantage in the market, and stability in the long run.
BI also refers to the information that is available for the enterprise to make decisions on. A data warehousing (or data mart) system is the backend, or the infrastructural, component for achieving business intelligence. Business intelligence also includes the insight gained from doing data mining analysis, as well as unstructured data (thus the need for content management systems).