There are two types of quotations – direct quotations and indirect quotations. Both need to be referenced in your notes, to avoid plagiarism.
When you're taking notes, try paraphrasing or summarising information instead of copying down text word for word.
When you paraphrase, you re-write what you've read in your own words using most of the key words from the text. Paraphrasing uses about the same amount of words as the piece of text you're quoting.
Summarising is when you only record the key points from the text. A summary is usually shorter than the piece of text it refers to.
Even though summaries and paraphrased information are written in your own words, they're still describing someone else's ideas, so they must be referenced in your notes.