Definition - What does Default Gateway mean?
Techopedia explains Default Gateway
A default gateway allows computers on a network to communicate with computers on another network. Without it, the network is isolated from the outside. Basically, computers send data that is bound for other networks (one that does not belong to its local IP range) through the default gateway.
Network administrators configure the computer’s routing capability with an IP range's starting address as the default gateway and point all clients to that IP address.