Source: BI Intelligence
“Structured” and “Unstructured” data are somewhat misleading terms. All forms of human communications have some structure (e.g., language) and machine-generated data typically has a structure because it is designed to have one. What we have is a continuum that goes from a highly rigid structure which is defined before the processing and mining of the data to highly flexible structure that is defined after the processing and mining of the data. The first end of the continuum has given rise in the 1970s to technologies such as relational databases that exploited the structure imposed on the data. The focus on “structured” data, i.e., data with predefined structure, continued until the 2000s when the increased mining of text documents (in the form of web pages) by online search and other web-based companies gave rise to the development of tools and technologies specifically designed to manage “unstructured” data, i.e., data without a predefined structure.