Hi,

Questionnaire is a set of printed or written questions with a choice of answers, devised for the purposes of a survey or statistical study.

A datasheet is document containing a summary of data or other useful information. It doesn't contain choices. Datasheets are similar to Excel sheets.

Questionnaires are more convenient for data collection, while datasheets are better for data analysis.

Hope this information is useful for you.

Thank you for your fruitful answer.

thank you