A Router Can Work With The Network Layer

If the Network Adapter on the router cannot transmit a data chunk as large as the source computer sends, the network layer on the router compensates by breaking the data into smaller units

Layer 3

Routers are computers designed to keep information that has been placed on the network media moving. Once on the media, a packet may go directly from the source computer to the destination computer OR go through a series of routers

in-between