DOC is the most popular text file format. Its full name is Microsoft Word Document, but the short version is more convenient and practical. This format was created for working with text documents in a paid text editor Microsoft Word office suite Microsoft Office. A file of this format contains not only a text document itself, but also a complete set of data on its formatting - paragraphs, indents, fonts, lists, text alignment, and much more. In addition, the DOC format makes it possible to include tables, charts, images in a text document. Working with such files is also available in many free programs or online services.
PNG is a raster image format developed by PNG Development Group. The name PNG is an abbreviation for Portable Network Graphic. This image format is used primarily on the Internet for posting on web pages, since PNG files use Deflate compression without losing quality. The development of this format was undertaken in order to replace the GIF format, to which there were many complaints. PNG's image quality and specifications were much better, but unlike GIF, it does not support animation and uses the CMYK palette.