PDF Means?

[mindriders]

Portable Document Format

[mammutgp]

PDF refers to a type of document format
It is a universal file format developed by Adobe^® that preserves all the fonts, formatting, graphics, and colour of any source document, regardless of the application and platform used to create it.

[Lisa_lee]

mindriders ,For what is PDF,you may refer to description in wiki below:
https://en.wikipedia.org/wiki/PDF