A copy of this book is available at the help desk.
"Works are published today in a dizzying range of formats. A book, for example, may be read in print, online, or as an e-book—or perhaps listened to in an audio version. On the Web, modes of publication are regularly invented, combined, and modified. Previous editions of the MLA Handbook provided separate instructions for each format, and new formats required additional instructions. In this groundbreaking new edition of its best-selling handbook, the MLA recommends instead one universal set of guidelines, which writers can apply to any type of source (www.mla.org)."
In short, MLA is one of the many writing styles that are used in the academic world. It is most commonly used in the liberal arts and humanities disciplines.
There are many differences between MLA and APA style so be sure to check with your instructor to see what writing style they prefer.