What are the native tokens?

As a cryptocurrency enthusiast and investor, I'm curious to know more about native tokens. Could you please elaborate on what they are? Specifically, I'm interested in understanding how they differ from other types of tokens, their role within a blockchain ecosystem, and any benefits or drawbacks they might possess. Are native tokens simply a means of value exchange or do they serve other crucial functions? Furthermore, how do investors assess the potential of a native token before making a purchase decision? Your insights would be greatly appreciated.