You paraphrase when you explain another author’s idea(s) in your own words, often with added context. Here's how to do it:

• Extract the gist. For example, one of the main arguments in Virginia Woolf’s A Room of One’s Own (1929) is: women have the right to education.
• When you paraphrase this, you might write something like: Woolf’s call for women’s right to receive education in her essay A Room of One’s Own is justified. Even though (some) women in the UK already had access to higher education since the 19th century, it would take until 1947 for women to be able to take full degrees at all UK universities. 
• Sometimes citing a direct quote is the best way to go. Make sure it is of added value before you do this.

Language tips

You can indicate paraphrases and thus avoid plagiarism with the following words/phrases:

• According to X, …
• Research by X suggests that …
• X comments / notes / states / observes that …
• The study by X emphasises / illustrates / concludes that …
• In an article by X, …
• In their study, X argues / suggests / claims / shows / that …

Try to avoid informal speech, e.g.: believe, love, hear, like, try, …