Keywords are important in developing good search terms to bring to databases and online search resources. They can be unique identifiers or themes. Combine keywords as search terms to narrow your searching into more focused and hopefully relevant results!
For your research, consider the following ideas for potential keywords:
Secondary sources are generally an analysis and interpretation of primary source evidence and artifacts/objects. They may be in the form of books or journal articles. Using secondary sources in your projects can help in the following ways: