To avoid plagiarism
Plagiarism is presenting someone else’s work or ideas as your own. Citing allows, allows authors to give credit to those works. Failing to cite and plagiarizing is an issue of academic integrity and can result in disciplinary action.
To give your work credibility
Citations also give your work credibility. It shows that you have done your research and that your ideas have the support of other authors and researchers within the field.
To help readers identify sources
Citations also help lead readers to the sources that you used. That way they can do further reading on the ideas that you present.