There are a multitude of reasons why cultures change. Some examples include innovation, diffusion and revolution. Although this is not a complete list, history shows that these factors have important implications on culture.
Dennis O'Neil, a professor at Palomar College, notes that innovations and inventions tend to either enhance culture or lead to culture loss. For example, the rise of computing technology has changed the way modern societies communicate and exchange information, but newer technologies have replaced traditional methods for much longer. Examples of radical changes led by technology include the rise of the automobile and the introduction of mass manufacturing.
Diffusion occurs when one culture adopts traits from a different culture. Perhaps the easiest and most well-known example of this would be the way Native Americans have become acculturated into Western society. Their distinctive way of life no longer exists in the way it once did. Again, this has happened throughout recorded history, an innovation that itself only came about because the Phoenicians brought their concept of the alphabet to Greece.
Revolutions are another way in which cultures can change. Entire political and economic systems, legal systems, rulers, and ways of life can change due to revolution; however, it is important to realize that revolution can change culture for better or for worse.