What is default routing and default route

Default Routing.
What do you mean by default routing and default route?.
Default routing is method of sending and receiving unattended or baseless routes from router. And default route is specific route which is given a function of redirecting all those baseless and unattended routes received or sending out of router to non specific destination.
There are multiple way of setting default route on routers, let say on cisco router.
1> If you are configuring default route on ip route enabled devices like cisco router, you can simply put below route in routing table.
# ip route 0.0.0.0 0.0.0.0 gateway-ip
Eg. # ip route 0.0.0.0 0.0.0.0 1.1.1.1
        # ip route 0.0.0.0 0.0.0.0 eth0(exit inte)

2> if you are about to configure default gateway on device where ip route is disabled,like on Cisco switches. then u have to put below configuration
#ip default-gateway gateway-ip
# ip default-gateway 1.1.1.1

3>. Configuring default gateway is not subjected to specific ip addresses. Even you can simply define whole network as default network, at this situation, network should be in routing table prior to configuration.
#ip default-network network ip
# ip default-network 1.1.0.0

Note: by default, default route is least specific route in routing table,routes will refer default route only if non of preferred route are exist in routing table. Any how you can make default route more specific by lowering (lower integer) it's administrative-distance