What are two types of SAs in the VPN negotiation?

In VPN negotiations, there are two primary types of Security Associations (SAs):

IKE SA (Internet Key Exchange Security Association): Establishes the secure channel for negotiating IPsec parameters.

IPsec SA (IP Security Security Association): Defines the parameters for the actual encrypted communication.

These SAs work together to ensure secure and authenticated VPN connections between gateways.