The Three Data Types


This course is related to data, which consists of three types: structured, semi-structured, & unstructured data.

Structured Data
It is the data kept in an electronic record, where each piece of information has an assigned format and meaning; for example, the data stored in a relational database.

Semi-Structured Data
It is a form of structured data that does not conform with the formal structure of tables and data models associated with databases but contains nonetheless tags or other markers to separate semantic elements and hierarchies of records and fields within the data; e.g., XML, HTML, and other markup languages.

Unstructured Data
It is the data stored outside a formatted database; for example, presentations, e-mail messages, complicated reports, voice mail, still images, and video.

Review: Data Types
    Which data type do e-mail messages belong to?

      Limited-structured data
      Semi-structured data
      Structured data
      Unstructured data
Result: