Deliberate plagiarism is purposely copying works from books, articles, webpages, or someone else’s paper and representing it as your original work.
Alternatively, accidental plagiarism occurs in a few different ways
1. Incorrectly citing another person’s works.
2. Failing to paraphrase another person’s works - even when citing it correctly.
3. Reusing your own previous papers and inadvertently representing them as a new idea.