Most of the people like to save their content in PDF file because it is much safer than any other file format. It is nice to know that we can easily protect our PDF file by password protecting the file. Protecting the filer will prevent unauthorized users to access your file and to gain the valuable content. We generally lock the file to prevent others from printing, copying or modifying any change to our content. In safety conscious world using password to protect your document is very useful and helpful.  The reasons behind using a security lock are many like to prevent others from copying, printing and editing your text. There are two ways to protect your PDF file the first is the user password that prevent unauthorized user from accessing your file.