Epigenetic modifications are chemical changes to DNA or associated proteins that affect gene activity without altering the underlying DNA sequence. These modifications can turn genes on or off, influencing how cells function and respond to their environment. Common types of epigenetic changes include DNA methylation and histone modification. These modifications can be influenced by various factors, including diet, stress, and environmental exposures. They play a crucial role in development, cellular differentiation, and can even be passed down through generations, impacting traits and health in offspring without changing the genetic code itself.