Originally Posted by pakiyabhai
I have got one ebook from a friend in .RAR format.
Extracting it , presents me
folder called images with images inside.
Although I am able to drag just the html to calibre and it works fine , I want to know what are the other files for , am I to compile them ? EPUB ?
You would find a similar group files if you unzipped an EPUB. Or decompiled a lit file. or decompiled a Mobi file. The "opf" file is the project file for any open ebook-style format. It contains references to all of the information in the other files.
Calibre will convert from the opf file if you let it and this is likely to produce the best conversion.