Quoting, paraphrasing, and summarizing are three ways of incorporating another writer's work into your own writing to support your arguments and points.
use an author as an authoritative voice
introduce an author's position you may wish to discuss
provide evidence for your own writing
make a clear distinction between the views of different authors
make a clear distinction between an author's views and your own.
Example taken from Purdue OWL (https://owl.english.purdue.edu/owl/resource/619/1/) with permission:
The original passage:
Students frequently overuse direct quotation in taking notes, and as a result they overuse quotations in the final [research] paper. Probably only about 10% of your final manuscript should appear as directly quoted matter. Therefore, you should strive to limit the amount of exact transcribing of source materials while taking notes. Lester, James D. Writing Research Papers. 2nd ed. (1976): 46-47.
A legitimate paraphrase:
In research papers students often quote excessively, failing to keep quoted material down to a desirable level. Since the problem usually originates during note taking, it is essential to minimize the material recorded verbatim (Lester 46-47).
An acceptable summary:
Students should take just a few notes in direct quotation from sources to help minimize the amount of quoted material in a research paper (Lester 46-47).
A plagiarized version:
Students often use too many direct quotations when they take notes, resulting in too many of them in the final research paper. In fact, probably only about 10% of the final copy should consist of directly quoted material. So it is important to limit the amount of source material copied while taking notes.
A quotation in your text must use the exact words of the source. When quoting a phrase, part of a sentence, or short passages of prose (fewer than 4 typed lines of prose), use quotation marks and a citation (credit the source). See MLA style examples below:
According to some, dreams express "profound aspects of personality" (Foulkes 184), though others disagree.
According to Foulkes's study, dreams may express"profound aspects of personality" (184).
Note: Always introduce quotations with an introductory phrase. No quotation should stand by itself as a separate sentence.
Example is in MLA Style (Source: https://owl.english.purdue.edu/owl/resource/930/08/)
human being to weep is a lessening of his capacity to be human – a defect
that usually goes deeper than the mere inability to cry…. It is very sad. (248)
Buffy, a small, delicate-looking blonde of superhuman strength, relies on Giles not only for adult support and coaching, but also for the research necessary to do that for which the Vampire Slayer has been chosen. In the third season, Giles was officially relieved from his Watcher duties, but he ignores that and continues as Buffy's trainer, confidant, and father-figure.
To help her fulfill her Slayer duties, Buffy can always turn to Giles (DeCandido 44).
And on "Works Cited" page.
DeCandido, Graceanne A. "Bibliographic Good vs. Evil in Buffy the Vampire Slayer." American Libraries Sept. 1999: 44-47. Print.
What can be summarized:
Lectures, presentations; textbooks; video clips; workshops; essays, journal articles, etc.