Primary sources can give direct evidence, specific details, and can provide a window into the feelings, reactions, and perceptions of a time. Primary sources might be used as an example or evidence in your paper. The downside of primary sources is that they may include bias, give a limited perspective, or lack context.
Secondary sources provide context and analysis to primary sources. They can give understanding to an artifact and respond to it, often with multiple perspectives. Secondary sources can be used to provide background information in your paper and to engage or further an argument.
For more information on how to use a source in your paper, check out these resources: