Default Gateway - squatchulator/cummings-tech-journal Wiki
A default gateway is a node that enables a connection between networks in order to allow machines on other networks to communicate. The 'default' part of the terminology relates to the fact it is often the first and default route taken.
One of the most common uses for a default gateway is to access web pages; a request is sent through the gateway before it actually gets on to the internet. Other use cases of default gateways include connecting multiple devices to a single subnet. In that scenario, the default gateway acts as an intermediary.
Put simply, default gateways are routing systems that allow requests to find the path of least resistance to their intended destination, even if the network protocols of the sender and the receiver are different.