"Data" is a plural noun that only has a plural form. In everyday English, however, this term is usually treated as an uncountable noun.

Technically speaking, the word "data" is a plural noun that only has a plural form. In everyday English, however, this term is usually treated as an uncountable noun (like "information"), and followed by a singular verb. Thus, both versions are widely accepted in standard English.

The data are used to develop new products and meet our customer needs. (Plural noun)

Your data was stored in a database for reporting and analysis. (Treated as an uncountable noun)

In formal language or academic writing, the plural form is preferred, and should be followed by a plural verb. After all, "data" comes from the Latin word "datum", which is the singular form of this noun.

The data are critical to the success of our project and must be analyzed properly.