The Inline spoilers plugin introduces functionality to Obsidian that allows users to hide and reveal text within their notes using the || syntax. Spoiler text is hidden until clicked, making it ideal for concealing sensitive or optional information. The plugin supports integration with various formatting styles such as bold and italics. Users can configure settings to always display spoilers or manage their visibility dynamically. This feature enhances note readability and organization, providing a seamless way to manage hidden text.