Java Programming

My husband is an IT graduate, he is also a JAVA certified programmer. He's been working for more than 5 years now. He traveled to FINLAND for some client thingy, I don't know exactly what he did there for almost two months and then came back in the Philippines after. I love his work even I don't know exactly how he works, all I know is that he is doing sort of programs, not the program we used to do on an event LOL. A programs of machines I guess especially in computers. Husband once told me that there are lots of programming language but he loves JAVA among them. I also heard about PDF library but I have no idea what it is. His line of work seems complicated for me but I love to learn what he is doing, I wanna try the easiest way to program using HTML code. How I wish! :Djava