Before diving into the specifics of the book, it is vital to understand the context of the Upper Intermediate level. According to the Common European Framework of Reference for Languages (CEFR), a B2 learner is defined as an "independent user."
This outcome-based approach is a primary driver for the popularity of the download. Students feel a sense of accomplishment after every unit, which is crucial for motivation at this demanding level.
Many websites offering free PDFs of copyrighted textbooks are either illegal or infected with malware. Here are legitimate ways to access the file: