What is the portal token bridge?
Could you elaborate on what the portal token bridge entails in the realm of cryptocurrency and finance? For those unfamiliar with this concept, could you provide a concise yet comprehensive definition? I understand that a token bridge serves as a connection between two blockchains, but how does the portal token bridge specifically function and what are its unique features? Is it a dedicated service for a specific type of tokens or does it cater to a broader range? Additionally, what are the benefits and challenges associated with utilizing a portal token bridge in the current financial landscape?