LyX is a document processor that provides the power and professional-looking typesetting of LaTeX with the familiarity of an easy-to-use graphical interface à la MS Word. Effectively, it provides the best of both worlds. For someone without knowledge of LaTeX, LyX is less imposing and has a smaller learning curve. But even seasoned LaTeX users who have no desire to leave their favourite text editor can take advantage of some of LyX’s features.
Documents typeset using LaTeX just look better than than their MS Word (or equivalent) counterparts. LaTeX has many well-known features to make document creation easy. However, it is some of its lesser-known features that together produce a professional-looking document.