This book review provides a comprehensive overview of Introducing Second Language Acquisition by Muriel Saville Troike and Karon Barto. The review covers the book's purpose, organization, content, and relevance for undergraduate and graduate students. The book explains the relation between first and second language acquisition, the stages of language learning, and the importance of concepts in second language learning. The book is published by Cambridge University Press and is relevant for those interested in gaining in-depth knowledge about second language acquisition.