The article reviews the rapid advancements in epigenetics over the past few decades, highlighting its role in linking genetics to the environment and disease. Epigenetics is defined as the study of molecules and mechanisms that perpetuate alternative gene activity states in the context of the same DNA sequence, encompassing both transgenerational and mitotic inheritance. The review discusses the interplay between epigenetics and DNA sequence variation, the implications of epigenetics for cellular memory and plasticity, and the effects of environmental factors on biology, disease, and evolution. It also explores new frontiers in epigenetics, such as the role of noncoding RNAs, DNA methylation, heterochromatin, Polycomb and Trithorax proteins, and 3D genome architecture in regulating inheritance and gene expression. The article emphasizes the importance of epigenetic inheritance across generations, particularly in mammals, and the potential influence of the environment on epigenetic changes. Finally, it highlights the potential benefits of epigenetic research for human health, including the development of personalized precision medicine and the exploration of lifestyle and 'mind–body' interventions.The article reviews the rapid advancements in epigenetics over the past few decades, highlighting its role in linking genetics to the environment and disease. Epigenetics is defined as the study of molecules and mechanisms that perpetuate alternative gene activity states in the context of the same DNA sequence, encompassing both transgenerational and mitotic inheritance. The review discusses the interplay between epigenetics and DNA sequence variation, the implications of epigenetics for cellular memory and plasticity, and the effects of environmental factors on biology, disease, and evolution. It also explores new frontiers in epigenetics, such as the role of noncoding RNAs, DNA methylation, heterochromatin, Polycomb and Trithorax proteins, and 3D genome architecture in regulating inheritance and gene expression. The article emphasizes the importance of epigenetic inheritance across generations, particularly in mammals, and the potential influence of the environment on epigenetic changes. Finally, it highlights the potential benefits of epigenetic research for human health, including the development of personalized precision medicine and the exploration of lifestyle and 'mind–body' interventions.