Roman economy was mostly based on agriculture and trade. The Romans traded within the empire and with other empires. The Romans built roads and great ships as a way of transport. They used silver, gold, and sometimes bronze coins as a means to trade for goods. The value of a coin was equal to the value of the precious metal it contained. A much larger bronze coin contained the same value as a smaller silver coin. The coins would have a picture of the emperor on one side and a message on the other. The message was used to bring attention to the accomplishments of the ruler. For example, some coins commemorated victories in wars while others were about the construction of important structures. Some of the coins used symbolism that would be clear to all. For example, the female figure of Felicitas was the personification of happiness and symbolized that things were going well for the Empire and emperor. The coins were really used as a means of propaganda since they were easy to mass reproduce and distribute.
Roman agriculture changed as the Empire progressed. In the beginning, the main source of agriculture were small estates cultivated and owned by small farmers. This was substinence farming since they only grew enough to feed their own families. However, as the empire became increasingly military and it became involved in more wars, the taxes also increased. The small farmers couldn't afford to keep their land and had to sell to a big landowner for protection and help. This caused the main agriculture unit to become the latifundia, or a huge estate owned by a single owner and operated by many slaves.