The citation style created by the Modern Language Association, MLA is most often used by the Humanities, which includes languages, literature, philosophy, visual & performing arts.
The Chicago Manual of Style is a comprehensive reference for authors, editors, proofreaders, indexers, copywriters, designers, and publishers in any field, though most often used in fields such as history, political science, and art.
Attribution is giving credit to creators of materials such as images, videos, audio files, and other creative works that were assigned a Creative Commons license. You will see these most often used with regard to Open Educational Resources (OER). Attributions are a lot like citations in that they help to maintain the history of an item including who originally developed it and when. Attributions differ from citations in that they also describe exactly how the resource can be shared or customized based on the provisions of the assigned Creative Commons license.