Documents, spreadsheets and slides do not have one answer on the Mac. Some of these replace the whole suite; others do a single job, for when a full office install is more than you need.
A free office suite for the Mac that opens and edits Word, Excel, PowerPoint and PDF files, with templates and cloud collaboration on top. It suits people who work with Office documents regularly.
A word processor built for scholarly and technical writing, with structured layout, style management and consistent formatting. It suits theses, technical reports and other long-form documents that need formal presentation.