You found a really appropriate online article, so you printed it and made copies of it to share in your social sciences class.
You used a quote from a Web site in your blog, noting the source within the text.
You write a research paper for school using many online sources, but you dont cite all of them because there are so many..
You created a PowerPoint presentation for your marketing class. You included the logo of a well-known hotel since that hotel is an example in your speech.