What is the total supply amount?

Could you please elaborate on the concept of "total supply amount" in the context of cryptocurrency? Specifically, I'm interested in understanding how it differs from other metrics like market capitalization or circulating supply. Additionally, could you provide an example of a cryptocurrency and its corresponding total supply amount? I'm curious to know if this figure is fixed or subject to change over time, and if so, what factors influence those changes. Your insights would be greatly appreciated as I'm seeking to deepen my understanding of this crucial aspect of cryptocurrency economics.