What is a difference between GRE over IPsec and IPsec with crypto map?

The difference between GRE over IPsec and IPsec with crypto map is that GRE (Generic Routing Encapsulation) over IPsec can encapsulate and transport non-IP protocols across an IP network, whereas IPsec with crypto map is typically used for IP traffic. GRE tunnels wrapped in IPsec provide a way to transport multicast traffic and other protocol types across an IPsec VPN, offering greater flexibility in the types of traffic that can be secured.