PDF (abbreviation for Portable Document Format) is a format created for the convenient presentation and use of electronic documents. PDF was developed by Adobe in 1993 and has since gone a long way before gaining popularity.
Initially, it was a closed format with a lot of restrictions, which is why it practically was not used widely. However, at this point, Adobe has eliminated many shortcomings. An official free reading program (Adobe Reader) was released, PDF is supported on most operating systems, the functionality was noticeably expanded, the file size was optimized, and much more.
As a result, the PDF format has become the generally accepted standard in the document flow, which is used by both individuals and organizations.