Summarising is when you write a brief overview of a longer piece of work in your own words. This could be a book, chapter or article.
Writing a summary is a particular type of assessment task (whereas paraphrasing is used in any assessment as part of your referencing).
Summaries are much shorter than the original text, but include the author’s main points. Below is an example of an article summary:
Malcolm, J. (2018). The importance of “maths talk” in early childhood. Young Learners, 9(12). 33-35.
In this article, Jennifer Malcolm discusses the role early childhood carers can play in helping young children develop their mathematical knowledge. She cites several studies which show that regular use of mathematical language by a carer, integrated into the day, provides children with a way to both express and further their own knowledge of mathematical concepts. Along with specific number vocabulary, Malcolm suggests key strategies for carers to use with young children including connection making, discussion, comparison and prediction.
(Note, like quotes and paraphrases, summaries must be attributed to the original author.)