The file stores slides with presentations and slide shows filled with graphics, audio, video, and textual information. The format is identical to the PPT file, except for the editing feature, and is a bit smaller. Can be opened only in preview mode and prevents other users from changing the structure and content of the presentation.
PNG is a raster graphic data storage format that uses lossless compression algorithm to Deflate. PNG was created as a free format to replace GIF. PNG supports three main types of raster images: grayscale image, a color indexed image and the color image. PNG format stores graphical information in a compressed form.