Images and videos can enhance your ability to communicate ideas to an audience. However, it is important to know that there are restrictions. Just a couple of things to consider before using images or videos that you found on the open web:
Copyright: published and even unpublished works are protected by copyright. Using visual works of others without attributing credit to creators is a form of plagiarism known as "copyright infringement."
According to the Salisbury University Academic Integrity Policy:
"Plagiarism occurs when a student intentionally or unintentionally deceives or disregards proper scholarly procedures; presents information, ideas or phrasing of another as if they were his/her own; and/or does not give appropriate attribution to the original source."
Creative Commons is a non-profit group who develops, supports, and stewards legal and technical infrastructure that maximizes digital creativity, sharing, and innovation.
Creative Commons licenses are a way for copyright holders to let other people know how their work can be used. At the most basic level a creative commons license requires that whoever uses it to give credit to the creator. It also allows for the creator to places some restrictions or conditions for their work to be used.
National Gallery of Art | Open Access - NGA Images - The National Gallery of Art implements an open access policy for digital images of works of art that the Gallery believes to be in the public domain. Images of these works are now available free of charge for any use, commercial or non-commercial.
Public Domain Images - Browse by category or search for images. Varied categories; the site also includes vintage photography and space images.
Library of Congress Prints & Photographs Online - Images from the Library of Congress, now in the public domain.
Search Tools for Creative Commons images and video