Exactly what it says it is--an introduction to SLA. I read it for a theory class could with Mitchell, Myles, and Marsden's "Second Language Learning Theories" (Third Edition) and where that one was richer and denser in detail, this book balanced it with a more straightforward attitude and easier access. I'm thankful for this one to help elucidate some of the issues. Also, the author formerly taught at my school, so that's a fun fact. Bear Down, UofA haha.