Scholarly articles are papers written by (usually multiple) experts in a subject and published in academic journals. The experts submit the papers they have written to be published in academic journals. These papers focus on specific topics and may be written about new research studies, case studies, reviews of previous research, or other research-related topics.
Academic journals are run by editors and published by publishing companies, universities, or professional associations. Most academic journals use a peer-review process to review articles for quality. Most academic journals have scopes, and they only publish articles that fit within the journal's scope. An academic journal that doesn't have a peer-review review process or has a very broad scope has warning signs of being low-quality.
A database is a collection of many different academic journals that can all be searched at once. Databases allow you to limit your search by certain filters, usually including by peer-review status. This is a way to feel more secure that you are being shown quality articles published in quality journals.
You can search a database by creating and submitting a search query. Based off your search query, you will get a list of articles (and other resources) as results.
A database is searched by creating a search query. A search query is the combination of search terms, filters, and code that you type or select before clicking the search button.
This is an example of a search in Academic Search Complete:
Turn your research question into search terms.
Look at that article's keywords. Keywords are usually written underneath the article's listing in your search results.
Different databases use different keywords. By reusing the keywords, you are learning to speak that database's "language".
Some databases will give you suggestions for search terms when you start typing in a search box. These are terms that the database absolutely recognizes.
Sometimes, the suggestions will be several terms in the same text box, all separated by the Boolean Operator or. This means that the search engine will search for all those terms at once.
Always check before you select a string of terms. Some of the terms might not be equivalent for your specific research topic!