What are dual language books in Portuguese?

Dual language books in Portuguese (or DLBs for short, as they are sometimes known) are books in which the whole book is written in two languages throughout, in as close a translation as possible. In many cases, the content of the dual language book or story is written in one language on one side of the open book, and the Portuguese language on the other side. The pictures allow you to see the Portuguese language used in context, as well as breaking up the text. In recent years, however, improved computer technology means that electronic dual language books, or ebooks, have appeared, meaning language learners can dip into libraries on computer, tablet, and Smartphone. In some cases, the dual language book is also accompanied by sound files in Portuguese, so that not only can learners see the words, they can also hear the correct pronunciation. You could argue that dictionaries are dual language books, although in practice most dual language books tell a story or impart information in Portuguese. You may also sometimes hear them described in Portuguese as parallel texts although these are also sometimes used to transpose an older type of language into modern words, as with Chaucer or medieval French.