Epigenetics is the study of changes in gene expression that do not involve alterations to the underlying DNA sequence. These changes can be influenced by a variety of factors such as environmental exposures, lifestyle choices, and developmental cues. Epigenetic modifications can alter the way genes are turned on or off, leading to changes in cellular function and potentially affecting an individual's health and disease risk. Understanding epigenetics can provide insights into how factors such as diet, stress, and exposure to toxins can impact gene expression and contribute to various diseases.