Chapter 4 Network Access Types of ConnectionsA physical connection can be a wired connection using a cable or a wireless connection using radio waves. Network Interface CardsNetwork Interface Cards (NICs) connect a device to the network. Ethernet NICs are used for a wired connection , whereas WLAN (Wireless Local Area Network) NICs are used for wireless. An end-user device may include one or both types of NICs. The Physical LayerThe process that data undergoes from a source node to a destination node is: The user data is segmented by the transport layer, placed into packets by the network layer, and further encapsulated into frames by the data link layer. The physical layer encodes the frames and creates the electrical, optical, or radio wave signals that represent the bits in each frame. These signals are then sent on the media, one at a time. The destination node physical layer retrieves these individual signals from the media, restores them to their bit representations, and passes the bits up to the data link layer as a complete frame .