The routing table can contain six types of routes:
A host route is a route to a host. In other words, the route is not to a network. Host routes have a subnet mask of 255.255.255.255 and a prefix length of /32.
A subnet is a portion of a major network. The subnet mask is used to determine the size of the subnet. 10.10.10.0/24 (255.255.255.0) is a subnet.
A summary route is a single route that references a group of subnets. 10.10.0.0/16 (255.255.0.0) would be a summary, provided that subnets with longer masks (such as 10.10.10.0/24) existed.
A major network is any classful network, along with its native mask. 10.0.0.0/8 (255.0.0.0) is a major network.
A supernet is a single route that references a group of major networks. For example, 10.0.0.0/7 is a supernet that references 10.0.0.0/8 and 22.214.171.124/8.
A default route is shown as 0.0.0.0/0 (0.0.0.0). This route is also called the route of last resort. This is the route that is used when no other route matches the destination IP address in a packet.