A book editor prepares a manuscript for publication. Their duties include anything from basic grammar checks to line editing and fact-checking. They work closely with authors to revise their documents to fit the requirements of the publishing house. Some individuals specialize in a particular genre within either fiction or nonfiction. Often an editor focuses on one aspect of the process, especially in larger companies. Some book editors take on all the parts of the review process. Excellent interpersonal skills are essential.