Extensive reading is a learner-centered approach in foreign and second language education that emphasizes reading large quantities of comprehensible and engaging texts for general understanding and enjoyment. Rather than focusing on detailed linguistic analysis, extensive reading promotes natural language acquisition through continuous exposure to meaningful input. This article presents a comprehensive and plagiarism-resistant academic discussion of extensive reading, examining its theoretical foundations, core principles, pedagogical benefits, classroom implementation strategies, and challenges. The study argues that extensive reading plays a vital role in developing reading fluency, vocabulary growth, learner autonomy, and overall communicative competence.