DNA ligases are essential enzymes that play a crucial role in the process of DNA replication and repair. They function by joining together the sugar-phosphate backbones of DNA strands, sealing nicks or breaks in the DNA. This action is vital for maintaining the integrity of the genetic material during cell division and in response to DNA damage. These enzymes work by catalyzing the formation of phosphodiester bonds between adjacent nucleotides. DNA ligases are particularly important in processes such as Okazaki fragment joining during lagging strand synthesis and in the repair of single-strand breaks. Their activity ensures that the DNA remains a continuous and stable molecule.