The lagging strand is one of the two strands of DNA that are synthesized during DNA replication. Unlike the leading strand, which is synthesized continuously, the lagging strand is created in short segments called Okazaki fragments. This occurs because DNA polymerase can only add nucleotides in a 5' to 3' direction, requiring the lagging strand to be synthesized in the opposite direction of the replication fork. During replication, the lagging strand is formed as the DNA unwinds, allowing the enzyme to create these fragments. After the fragments are synthesized, another enzyme called DNA ligase joins them together to form a continuous strand. This process ensures that both strands of DNA are accurately replicated for cell division.