As one of the most important components of language, vocabulary and the way it can be taught have been a long standing concern of many teachers. This book addresses vocabulary learning in the context of task-based teaching. It compares the contribution of input-oriented and output-oriented tasks to L2 vocabulary comprehension and production. It offers a theoretical review of some of the current views in this area followed by an empirical analysis of the issue. This book is suggested for second language learners at various proficiency levels as well as teachers and materials developers who are concerned with vocabulary learning.