Dating methods are techniques used by archaeologists to determine the age or chronological position of archaeological remains, sites, artefacts, and cultural deposits. Establishing chronology is essential in Archaeological Anthropology because it helps reconstruct the sequence of human cultural development, technological change, migration, settlement, and interaction. Dating methods are broadly divided into relative dating and absolute dating. Relative dating determines whether an object or archaeological deposit is older or younger than another, without providing an exact numerical age. Absolute or chronometric dating, in contrast, attempts to provide an age in years. Two important methods of relative dating are stratigraphy and typological dating. Stratigraphy is one of the oldest and most fundamental methods of relative dating in archaeology. It is based on the study of the successive layers, or strata, of soil and cultural deposits at an archaeological site. The basic principle is that, in an undisturbed sequence, the lower layers were deposited earlier than the upper layers.