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.
This format is used for exchanging graphics data between SAPR programs. It was initially created for AutoCAD in 1982. It contains information regarding vector graphics in binary or ASCII. It’s used as an open alternative to the closed DWG format.