Definition courtesy of Merriam-Webster:
Plagiarize: to steal and pass off (the ideas or words of another) as one's own: use (another's production) without crediting the source
Make every effort to document and acknowledge your sources!
Useful online citation resources:
Microsoft Word: Office, New, Report, Academic Papers and Reports, Choose Formats APA, MLA, etc.
Databases: Look for the Cite Link in the toolbar on the right hand side of the screen.