Make a list of keywords that describe your topic. For example, "heart disease" and "cardiovascular disease"
When you do a keyword search you are looking for articles that have that keyword anywhere in the text. For example, using the keyword climate change you might find an article all about Giant Squids that mentions climate change one time on the last page. Keywords help you do a broader search, but keywords searches also give you results that may not be relevant to your topic.
When you do a subject search you are looking for articles that are about that subject. For example, using the subject climate change will give you articles about climate change. It can be hard to figure out what the right subject term is, but once you find it it will always take you to results that are about your topic.
Use your keywords to search the library databases. Think of important words or phrases that describe your topic including synonyms and alternate terms.
For example: Searching for flu vaccine information?
Use Advanced Search Techniques