Definition: To steal and pass off (the ideas or words of another) as one's own : use (another's production) without crediting the source. --Merriam-Webster's Online Dictionary
To avoid plagiarizing, you should give credit when:
1. Quoting another person’s actual words
2. Using another person’s ideas, opinion, or theory
3. Using another person's creations like art work, images, illustrations, etc.
4. Borrowing facts, statistics, or other illustrative material, unless the information is common knowledge
