Doesn't MLA have something to do with how the paper looks too?  

Yes. MLA does recommend that every paper appear in a certain way. According to the MLA Handbook, papers should be typed on 8 1/2 by 11 inch white paper. There should be 1 inch margins all around your text. Paragraphs should be indented one-half inch (about five letter spaces). Double-spacing of all text including works cited is required. Pages are numbered in the upper right hand corner of every page one-half inch from the top and one inch from the right-hand margin. Your last name should appear before the page number. Pages should be joined together in some way. MLA recommends using a paper clip. (However, most teachers prefer pages to be stapled in the upper left-hand corner.) 

There are other styles for documentation: 

    You might have heard about APA Documentation. APA stands for the American Psychological Association. This style is 
used for papers in psychology and other social sciences. 

     CBE (Chicago Manual of Style) is another method of documentation used primarily for history and philosophy.