Data is classified as either structured or unstructured. Structured data resides in fixed fields within a file such as a spreadsheet, while unstructured data refers to free-form text or media in text documents, PDF files and video.[4] An estimated 80% of all data is unstructured and 20% structured.[5] Data classification is divided into content analysis, focused on structured data and contextual analysis which looks at the place of origin or the application or system that generated the data.[6]