Turabian, Kate. A Manual for Writers of Research Papers, Theses, and Dissertations: Chicago Style of Students & Researchers, 8th ed. Chicago, IL: The University of Chicago Press, 2010. 42.
Paraphrase when you can state what the source says more clearly or concisely or when your argument depends on the details in a source, but not on its specific words.
Booth, Wayne et al. The Craft of Research, 4th ed. Chicago, IL: The University of Chicago Press, 2016. 200.
Summarize when details are irrelevant or a source does not warrant much space.
Booth, Wayne et al. The Craft of Research, 4th ed. Chicago, IL: The University of Chicago Press, 2016. 200.