MLA Handbook by 
Previous editions of the MLA handbook focused on many different publication formats -- (book, book chapter, journal article, web page, YouTube video. etc.) Each format had its own set of rules for creating a citation. In the old model, a writer would ask "How do I cite a book [or DVD or web page]?"
Since the 8th edition, the focus is on core elements (author, title date, etc.) common to most sources (books, journal articles, web pages tweets, etc.) and universal, flexible guidelines. In the new model, the writers asks, "Who is the author? What is the title?" and so forth regardless of the nature of the source.
Some Definitions
Element: The different pieces of information that may exist in any citation: Authors, Title, Other contributors, Version, Number, Publisher, Publication date, and Location.
Container: This word refers to larger works (like a database or newspaper) that contain smaller works (like individual articles). The smaller works are "nested" within the larger works.
Location: This word no longer refers to the place of publication. It now refers to page numbers, URLs, permalinks, and any Digital Object Identifiers (DOIs).
