The Completed Area plugin streamlines task management in Obsidian by moving completed to-do items into a designated 'Completed' section. Users can toggle this feature through a sidebar icon or a default shortcut (Control + Enter). The plugin allows customization of the completed area’s header level (h1 to h6) and header name, with defaults set to h2 and 'Completed,' respectively. Users can also choose to disable the sidebar icon and rely solely on commands for a cleaner interface.