The purpose of a style guide is to provide uniformity in writing and documentation/citation and in formatting documents of many kinds. Following a standard style guide ensures that your paper or presentation is professional-looking and readable.
You will likely encounter style guides beyond college, as you write and present in your chosen career. Most publishers have style guides of their own, and many businesses or organizations have guidelines for content produced by employees. Whether your job requires you to publish articles and books, write website content, present reports or draft intraoffice memos, knowing how to use a style guide will help you keep your work uniform.