You like bought software online, but the operating instructions is a .pdf file. You want to read some academic thesis, but they are not .html or .doc documents, they are also .pdf file. So, you really need a PDF reader.
1. OPEN
First of all, you must confirm that there is a PDF reader installed in your computer. Nobody can open a PDF file without the help of a PDF reader. It is simply to open a PDF file, what you need to do is click 
button and choose the file. Or, if the file is just before your eyes, just double click the file.
2. READ
These buttons are used to change the size of the page you view.
If you want to rotate the page you read, these two buttons are useful.
You could choose the way of reading, one page on one screen or two pages on one screen and others.
These buttons in sequence means: go to the first page of the .pdf file, go to the previous page, go to the next page, go to the last page.
move backward, move forward
More about PDF
PDF is the abbreviation for "Portable Document Format"
The Portable Document Format (PDF) is the file format created by Adobe Systems in 1993 for document exchange. PDF is used for representing two-dimensional documents in a device-independent and display resolution-independent fixed-layout document format. Each PDF file encapsulates a complete description of a 2-D document (and, with Acrobat 3-D, embedded 3-D documents) that includes the text, fonts, images, and 2-D vector graphics that compose the document.
08/29/2007
Brendan Gleeson