What is adobe portable document format

Portable Document Format (PDF) is a file format used to present and exchange documents reliably, independent of software, hardware, or operating system. The goal was to make it easier for people to distribute documents without the need to print them and to enable anyone to capture documents from any application. PDF files are primarily meant for viewing, not editing. It is useful because it allows the document to be viewed and printed the same way on any device. Adobe distributed its Adobe Reader software to support the original PDF format. The PDF is now an open standard, maintained by the International Organization for Standardization.

Based on the PostScript language, each PDF file encapsulates a complete description of a fixed-layout flat document, including the text, fonts, vector graphics, raster images. The graphics model at the heart of Adobe PostScript paved the way for the development of Adobe PDF. PDF documents can contain links and buttons, form fields, audio, video, and business logic. PDF is widely used to share documents via email and web-sites, and to print them from smartphones and tablets.

Postscript 

Postscript is a programming language that describes the appearance of a printed page. It can handle graphics and standard features of programming languages such as if and loop commands. Users can convert Postscript files to the Adobe Portable Document Format using the Adobe Acrobat product.

The PDF combines three technologies: 

A subset of the PostScript page description programming language.

A font-embedding/replacement system.

A structured storage system.

How to edit or make changes to a PDF file

Portable Document Format (PDF) is a common format for sharing final versions of files. Opening and viewing a PDF file is pretty simple. Most modern web browsers will open PDF files directly in your browser window instead of downloading them to your computer.

Many programs can save documents in PDF format, but if you want to edit a PDF file, then you'll need an app which allows you to modify the file. To add or edit text in a PDF that was made in an Office program like Excel or Publisher, start with the original Office file. Open that file in your Office program, make your changes, and then save the file in PDF format again.

To convert a PDF and edit it you can use a third-party PDF converter tool to import your PDF into an Office file format, make your changes, and then save the file in PDF format again.

Popular PDF Editors 

Foxit Reader is a lightweight alternative to Adobe Reader.

PDF2DOC allows you to convert a PDF document to Microsoft Word DOC format.

AbleWord has some simple editing functions including adding rectangles, highlighting zones, plus the ability to strikeout or add text.

PDF-XChange Editor replaces the Viewer app, bringing with it some impressive features

PDF converter like Smallpdf, which is a free app that runs in your web browser.