Slideshare is a free online platform that allows users to upload and share presentations. It can be used to create a profile, upload presentations, share with others, and comment on and rate other presentations. Slideshare was founded in 2006 in San Bruno, California by Rashim Sinha, Jonathan Boutelle, and Amit Ranjan and supports formats like PowerPoint, OpenOffice, and PDF files. Teachers and students can use Slideshare to upload class presentations and interact with others.