PDF (Portable Document Format), is not just a well-known and convenient format, but the only one that has been standard since 2008. It was developed by the Adobe Systems team. The developers of the format set themselves the task of creating such a format for displaying the document so that the document opens and looks the same on any device. The PDF format is used for storing and transmitting text and graphic information on the network, for example, for transferring letterhead to the printing industry or posting a questionnaire on the website. Great for demonstrating developments: easy to show, edit - difficult. This complicates the theft of intellectual property. Well, the ideas of a "paperless office" are received with a bang by everyone who thinks about ecology on the planet.
PNG is one of the popular formats in web graphics. It was proposed in 1995 at the Usenet conference as a free alternative to licensed GIF. Since October 1, 1996, it exists as a full-fledged graphic format supported by all browsers and graphic editors.PNG is one of the most popular formats due to its good compression without loss of quality, fast loading, transparency function, clear image borders. In practice, .png is ideal for saving images with a small number of colors, as well as graphics with transparent areas. Logos, icons, badges, diagrams, scanned copies of documents are usually placed on sites just in .png format