Plagiarism is the act of taking someone's work or ideas and using them as your own. This could be something as serious as taking someone's research and using it as your own or something as small as copying a picture off the internet that is watermarked.
There will be zero tolerance for plagiarism, all work must be the students own ideas and work. While researching from websites that were created by someone else, those ideas are not to be used unless the creator is credited for the work. This also goes for using someone else's words (quotes), picture's, research, etc..
Websites to help better understand plagiarism and ways to avoid it:
https://www.plagiarism.org/article/what-is-plagiarism
https://www.scribbr.com/plagiarism/how-to-avoid-plagiarism/