When you fill out a survey, you aren’t given a long string of questions in paragraph form with one text area for your response. Not only would it be hard for you, the survey taker, to provide all the requested information; but it would also be incredibly time intensive for the survey analyzer to organize and understand all of the response data.
Instead, surveys are organized with questions and corresponding answer fields. All of the survey information has its own designated area, and is easy to access.
Like survey fields, metadata fields organize the individual pieces of data about other data.