A digital library provides access to scholarly digital sources including subscription databases and encyclopedias for easy access to accurate information. If you are doing academic research you should use this or the library catalog for your research.
A database is like a digital file cabinet; it organizes a collection of information to make the information searchable and accessible. A collection is any group of information/knowledge sources (magazine articles, books, papers, images, sound files, and videos).
You will see the list of the paid digital resources (databases and encyclopedia) available for you to start using for your research assignments. Each database has a brief description of what they offer for your research.