SlideShare is a website that allows users to upload presentations in various file formats such as PowerPoint, PDF, Keynote, and OpenDocument. Users can view presentations uploaded by others, and share their own presentations publicly or privately on blogs, websites, Twitter, and Facebook. SlideShare is used by organizations like the White House, US Army, US Navy, and NASA. It partners with companies like Twitter, Google Hangouts, and LinkedIn. When uploading presentations, users are advised to use visuals instead of text and add relevant tags and descriptions.