DNA methylation and histone acetylation are examples of epigenetic processes. Epigenetics refers to the study of changes in gene expression or cellular phenotype that do not involve alterations to the underlying DNA sequence. These changes can be heritable and reversible and play a crucial role in regulating gene activity and determining cell identity during development and in response to environmental cues. DNA methylation involves the addition of a methyl group to DNA molecules, typically at cytosine residues, which often leads to gene silencing. On the other hand, histone acetylation involves the addition of an acetyl group to histone proteins associated with DNA, leading to relaxation of the chromatin structure and increased gene expression. Both DNA methylation and histone acetylation are important mechanisms for regulating gene expression and are fundamental processes in epigenetic control.