Which coin has a head on one side?

In the realm of cryptocurrency and finance, there's often a focus on digital assets and their underlying technology. However, let's take a step back and explore a more traditional form of currency: coins. Now, I'm curious to know, which coin typically features a head on one side? Is it the penny, with its iconic portrait of Abraham Lincoln? Or perhaps the quarter, which boasts the image of George Washington? Or could it be another denomination entirely? This question may seem straightforward, but it's a reminder that even in our digital age, traditional forms of currency still play a vital role.