2 Added disclaimer.
source | link

A device that has an IP address exists within a network.

A Router is a device who's primary purpose is to pass traffic between networks.

For a Router to pass packets between two networks, it must exist within both networks.

The Router will have an "arm" inside each network -- or as we call it, an interface. And the way an interface exists within a network is by assigning it an IP address within the network.

Hence, when configuring a router, each interface receives an IP address to identify the networks which that Router belongs within.

Disclaimer: The link above is to my blog. My blog is not monetized. I make no profit from you reading it. I am providing a link simply for your (and any other reader's) benefit.

A device that has an IP address exists within a network.

A Router is a device who's primary purpose is to pass traffic between networks.

For a Router to pass packets between two networks, it must exist within both networks.

The Router will have an "arm" inside each network -- or as we call it, an interface. And the way an interface exists within a network is by assigning it an IP address within the network.

Hence, when configuring a router, each interface receives an IP address to identify the networks which that Router belongs within.

A device that has an IP address exists within a network.

A Router is a device who's primary purpose is to pass traffic between networks.

For a Router to pass packets between two networks, it must exist within both networks.

The Router will have an "arm" inside each network -- or as we call it, an interface. And the way an interface exists within a network is by assigning it an IP address within the network.

Hence, when configuring a router, each interface receives an IP address to identify the networks which that Router belongs within.

Disclaimer: The link above is to my blog. My blog is not monetized. I make no profit from you reading it. I am providing a link simply for your (and any other reader's) benefit.

1
source | link

A device that has an IP address exists within a network.

A Router is a device who's primary purpose is to pass traffic between networks.

For a Router to pass packets between two networks, it must exist within both networks.

The Router will have an "arm" inside each network -- or as we call it, an interface. And the way an interface exists within a network is by assigning it an IP address within the network.

Hence, when configuring a router, each interface receives an IP address to identify the networks which that Router belongs within.