MLA style was created by the Modern Language Association, which is what MLA stands for. It is a set of rules for publications, including student research papers, commonly used in humanities disciplines. It was created in 1931 so that writers could have a uniform style to follow for quotations, punctuation, footnotes, and bibliographical references. It includes rules on how to format your papers, in-text citations, and bibliographies (works cited).
MLA updated its style manual in the spring of 2016, the 8th Edition.
NOTE: In Spring 2021, MLA issued its MLA HANDBOOK 9th Edition