This lecture introduces the theory of abelian groups, focusing on p-abelian groups and their structure. The instructor explains the classification of finite abelian groups, emphasizing the analysis of p-groups. Various examples are provided to illustrate the concepts, such as groups with prime orders. The lecture covers the definition of p-abelian groups and their cardinality, highlighting the importance of understanding their structure. The instructor discusses the properties of p-groups and their subgroups, leading to a deeper comprehension of group theory. The lecture concludes with a proof regarding the structure of p-abelian groups, demonstrating the application of theoretical concepts in group theory.