Why are databases useful to researchers?

because librarians use them to find books for their libraries

because they are part of the "invisible web" and can only be accessed in a library

because they include scholarly articles that add credibility to your research

because you have to pay for the service

because they include scholarly articles that add credibility to your research.

A database is a collection of data, most often stored and accessed electronically from a computer system. Databases are useful because they include scholarly articles. These articles have been peer-reviewed, which means that they meet the minimum requirements of scholarly research. Using these resources will add credibility to your research.

where are the multiple answers?