In ancient times, technology was basic compared to today. There were basic things such as the calendar and books to more complex such as architecture. Roman architecture particularly stood out because of the arches, long lasting concrete, and aqueducts. National time period was a big change from ancient. New building materials such as steel were being used. Transportation such as railroads came about. Also new energy sources such as light was introduced. Modern times has yet again brought new materials. Architecture is starting to take the environment into consideration. LEED certified buildings are being implemented. Most notable in technology is the computers that we use in our everyday lives gets introduced in this time period.