Plagiarism comes from a Latin word for "kidnapper." Using the ideas or words of others without acknowledging the source is plagiarism. This is true even if the ideas of someone else are paraphrased or summarized. In scholarly research, plagiarism is considered unethical and dishonest.

Copyright is concerned with more than properly crediting sources. Excessive use of another's original work, even if the source is properly acknowledged, may be a copyright infringement.

Plagiarism is abuse of ideas and words from the work of someone else. Copyright is only concerned with original expression. Ideas and words alone cannot be copyrighted without originality.

Copyright is addressed in both federal statutes and case law (legal decisions delivered by the courts).  Except for some very specific statutes that apply to the results of scientific research for the government, plagiarism does not appear in federal statutes.