LyX is a document processor based on WYSIWYM (What You See Is What You Mean) rather than WYSIWYG like traditional word processors. It acts as a front end for LaTeX, allowing users to focus on content over formatting. LyX handles formatting tasks like page numbering, footnotes, and cross-references automatically after content is written. It excels at features for academic writing like mathematics, lists, tables, and cross-referencing. The document provides instructions on how to get started using LyX and resources for learning more.