All of our digital books are in PDF format and are eBooks. eBook is a generic term for all formats of printed items that are read on a digital device.
We understand the confusion concerning the various formats with e-pub being a very common format. Just as PDFs require a PDF reader, such as the free Adobe Reader, e-pub also requires a dedicated reader, which is also free.
Our management is looking into e-pub in the long term. As we have hundred of thousands of PDFs in our inventory, this must be taken into consideration with all of our products. It has also been suggested that we publish in both formats, and this is also getting looked into.