Slideshare is a website where users can upload PowerPoint, PDF, and other file presentations and share them with others. The document discusses how Slideshare can be used for educational purposes at different grade levels and its benefits and limitations. Teachers can use Slideshare to find presentations for teaching, create collaborative groups with other classes, and have students publish and comment on each other's presentations. For younger students, it allows storytelling and vocabulary building. For teens, it promotes creativity, sharing ideas, and group work skills. For high schoolers, it encourages intercultural knowledge and real online communication through embedding presentations in blogs.