Multidisciplinary databases contain articles and other content across a variety of disciplines which means it's less specialized but good starting points for locating articles. Think of them as the "one-stop shopping" sources of the database world. You can find articles ranging from business to science to the arts.
Subject-specific databases provide a more limited but also more specialized "bucket" of content for you to search through. They are useful when you're doing research in a specific field or discipline. You can compare them to visiting a doctor who specializes in one type of medicine and has extensive and deep knowledge about it.
What should you do if you find an interesting article in a database but no link to the full text?
Click on the purple "Check for full text" button – this button will attempt to connect you to the full text article if it is owned by the UW.