what is the use of NextHope in the default router.
The next-hop is the next L3 device that is closer to the destination ip address. So if you had this route
ip route 192.168.5.0 255.255.255.0 192.168.12.1
this is telling the router that to get to the network 192.168.5.0/24 you need to send packet to the L3 device with the address of 192.168.12.1.
Note that this L3 device could be a router, firewall, L3 switch.