People raise their awareness of the issue of environmental protection in recent years. One of the actions is to build the paperless world. PDF format is essential for boosting this process. Many people nowadays can ...

One of the key features of PDF format is the great security. There are basically two kinds of PDF password, the owner password and user password. The authors of the PDF can restrict readers from ...

Nowadays almost every computer has some kinds of software which is able to read PDF files, for example , Adobe Reader or Foxit Reader and so on. Why is that? Because PDF has become the ...