"Plagiarism is the representation of another author's language, thoughts, ideas, or expressions as one's own original work. In educational contexts, there are differing definitions of plagiarism depending on the institution. Plagiarism is considered a violation of academic integrity and a breach of journalistic ethics. It is subject to sanctions such as penalties, suspension, expulsion from school or work, substantial fines and even imprisonment"
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Above picture is basically dragged from a website but if I had not given any source from where I had put it in the essay then it would be as claiming someone else things yours without even notifying them. So basically this is known as plagiarism. We should not encourage plagiarism as one mind get used by other without the creator getting the credits. For example it could also be seen as stealing someone else's food cooked by other and presenting to other as if you have cooked the food, here the original creator of food is not getting acknowledged. So plagiarism is not good in any term even here in steem.
"I have read and understood the Steemit Etiquette on Steemit Community and will do my best to embrace them"Source