MLA format is used for writing papers and essays in liberal arts and humanities subjects. It provides a standardized way to cite sources using both in-text citations and a Works Cited page to avoid plagiarism. MLA format guidelines specify using Times New Roman 12-point font, double spacing, 1-inch margins, and including a header with the author's last name and page number on each page. Sources should be cited both in-text with the author's name and page number and fully in an alphabetical Works Cited list, with examples given for different source types like books, websites, and multiple authors.