Vocabulary is an indispensable component of language that affects different aspects of it such as the communication ability. Despite its importance, vocabulary teaching and learning in EFL contexts is mostly limited to classroom which cannot provide enough input for learners. Hence, it is reasonable to look for alternative ways to help learners in the process of vocabulary learning. Mobile Assisted Language Learning is one of such ways that have created new ways to help learners in the process of language learning and has the potential to extend vocabulary learning and teaching outside of the classroom. Therefore, the present book can make a theoretical and pedagogical contribution to the field of language teaching. Its significance lies in offering a new practical approach to vocabulary instruction- i.e. MALL- that extends teaching outside of the classroom and makes language learners responsible for learning. Moreover, MALL can be used in both academic and nonacademic contexts, with large number of students and it can be used in different approaches e.g. reciprocal and nonreciprocal and at anytime and anywhere.