Data-Datum | Commonly Confused Words

Data

/ˈdeɪtə/

Facts or information used for analysis or to make decisions

That data is for them.That data is about the whole city.His research suffered due to corrupt data files.

This word has no antonyms

A single piece of information or fact, often used as the singular form of data

The datum indicated a rise in visitor numbers.Researchers analyzed each datum individually for accuracy.A single erroneous datum skewed our results.

Data is the plural form, whereas datum is the singular form.
Think of data as similar to criteria, and datum as similar to criterion.
Use data when referring to multiple pieces of information, while datum refers to a single piece.
Data is often used as a collective noun in modern contexts, similar to information.
Remember: one point of data is a datum, many points are data.