How much is 1 denarius in Jesus time?

Could you please clarify for me the value of 1 denarius during the time of Jesus? I understand that it was a Roman coin, but I'm curious about its purchasing power and how it compared to other forms of currency in circulation at that time. Was it a common coin used by the average person, or was it more valuable and reserved for specific transactions? Additionally, how does its value compare to modern currencies, if at all? Thank you for your insight.