What is the network mask for a 30 network?

Could you elaborate on the network mask for a /30 network? I'm aware that the network mask defines the network portion and host portion of an IP address, but I'm not entirely clear on how it applies to a /30 subnet. Could you explain the specifics of the mask, how it differs from other subnet masks, and why it's typically used in certain network scenarios? Understanding the /30 mask would help me grasp subnetting and IP addressing concepts more thoroughly.