Ethical use of information means using information ethically and properly. There are two ways that deal with this concept:
They are the issues of plagiarism and copyright.
It is important to give credit where credit is due and use other people's work correctly. Even though information, words, and ideas are not concrete, they still can be stolen and those that do that can get into trouble.
It is important to ethically use the resources you gather for your own project, paper, or research. The way to do this, is to correctly cite your sources both in the text of your paper and in your references, works cited, and/or bibliography.