Is Summarize a Real Word?

To summarize means to sum up the main points of something — a summarization is this kind of summing up. Elementary school book reports are big on summarization.

Is there such a word as summary?

1. Summary, brief, digest, synopsis are terms for a short version of a longer work. A summary is a brief statement or restatement of main points, especially as a conclusion to a work: a summary of a chapter.

Is Summarise correct?

is that summarize is to prepare a summary of something while summarise is to prepare a summary of something.