In a router, what is default route used for?

If you are configure internet on router use default route otherwise if you have small scal business you can use default routing, its no prevation other network packet.

It is a route, where all packets are forwarded to when no specific route can be determined for a provide IP destination address

the default route in a router that is where all packets are routed to send or receive

In Cisco router, default routes are static and are also referred to as the gateway of last resort. a default route is a route a device sends traffic to if no other options exists, it's their last attempt to get the data to its destination.

The default route is used to forward packet to unknown destination by implementing route policy.

The default route is used for forwarding unicast packets from the source which is (any IP address have any subnet mask) to its destination or next hop .

router used default route inbound and outbound traffice allow and used for indirectly route.

a default route for any networks to which the ASA is not directly connected

The answer can be different according to the implications.

As stated by previous commentators, network specificity is ignored and thus any packet from any source passing through can be router to the next router that should be either the only or the preferred direction for the flow of all data. On the other hand, it can also be used to minimize the routes in a routing table and thus an option for optimization for routing tables.

Similarly, it can also be used in hardware that have limited resources (RAM/CPU) and can help retain it for a certain more amount of time.

used for unknown destinations

the default route usedwhen no specific route can be determined for a given network