All original, creative works are protected by copyright. The copyright in images and artwork that are found on the internet is owned by the person/company that created and designed them. If you choose to use an image that you did not create for anything other than personal use, then you must either ask for permission from the copyright owner to use their work or make a determination if your use is covered by the fair use exception under the U.S. Copyright Act. Information on fair use and copyright can be found at www.lib.purdue.edu/uco.
Trademarks are generally logos and slogans that are associated with a company. If you want to incorporate one into your design, then you should seek permission from the company that owns the trademark. All Purdue logos such as the Unfinished P, the Boilermaker train, etc. are protected trademarks. To obtain permission to use these trademarks, contact the Purdue Trademarks and Licensing Office - Trademarks and Licensing - Purdue University.
Using a copyrighted work or a trademark without the owner’s permission or covered under a legal exception will be considered an infringement. Penalties include paying a significant fine and/or going to prison. It is important to be aware of the laws and to be respectful of intellectual property rights.