Peer learning has become a topical in higher education reform, especially in areas whereby lecture-based approaches prevail. This paper will review how peer learning enhances conceptual learning among college students. The study uses the Zone of Proximal Development framework (Vygotsky) and the social constructivist models to examine the relevance of organised peer interaction in promoting a deeper learning process than the same individually or with the teacher. A literature review (2000-2024) was carried out methodically with special focus made on the empirical studies in Indian and global settings. Case insights are that peer learning grows cognitive processing, promotes active learning and decreases academic anxiety. Nevertheless, peer learning depends on a close scaffolding by the instructors to avoid the influence of misinformation and unequal participation. The results indicate that peer learning cannot be regarded as an auxiliary exercise but a fundamental pedagogical tool that promotes the subject mastery and other transcendental skills including communication, critical thinking, and teamwork. At the end of the paper, some recommendations have been made on the policy, curriculum reform, and future research directions.