An eBook is an electronic book, that can be immediately downloaded and read on your computer or hand-held device. It contains the same information as a regular book.

You will find them in various formats and until the industry has a standard accessible in all devices these various formats will exist.

PDF format is a popular format for ebooks. All platforms are able to gain access and read PDF formatting. So regardless if you have a PC or Mac, you will be able to open and read a PDF file. PDF requires the Acrobat Reader but this software comes on many new computers and if not included, it's a free downloaded from Adobe http://www.adobe.com. There are still many who prefer printing out the pages of an ebook to read and PDF files have always been good for this purpose.