Copyright protects original creative works and ensures that creators receive due credit for their ideas and expressions. It is illegal and unethical to use someone else's copyrighted work without permission. While the copyright symbol is not required, copyright exists automatically when a work is created. As the copyright owner, one has exclusive rights over how their work is used, including copying and adapting it. Fair use allows limited use of copyrighted works for purposes like commentary without permission. Plagiarism involves taking credit for someone else's ideas or words without citing the source, even if rephrased. Proper citation is always required to avoid plagiarism.