A local area network (LAN) adapter is a small piece of hardware that allows a computer to join a LAN. It can be internally installed in the computer as a network interface card (NIC), or it can take the form of an external adapter. Whether internal or external, the LAN network adapter (more correctly referred to as a LAN adapter or network adapter) also comes in two flavors: wired or wireless. To connect to a network wirelessly, the network’s router must also be a wireless model. Typically, wireless routers optionally and additionally support a limited number of wired connections.
At one time, virtually all computers came with a wired network adapter. It is easily identifiable by the RJ-45 port that resembles a large telephone jack. This jack accommodates an Ethernet cable that runs from the computer’s NIC to the network’s router. A wired LAN is a very fast, very secure type of network with one main disadvantage: computers must be tethered to the router. This limits the distance machines can be from the router and involves unsightly cables. If cables need to be professionally installed throughout a building, this is an additional expense.
While most desktops still come with an Ethernet card or NIC, some laptops no longer have a NIC by default. The mobile LAN network adapter of choice is the wireless model, which incorporates a transmitter and receiver to communicate with a wireless router. Network data travels via radio frequency (RF) waves, broadcast throughout the local area. To keep the data private, LANs are typically encrypted. Joining the LAN requires submission of a preset password.
Third-party or aftermarket network cards of many varieties are extremely affordable. A wired LAN network adapter can be had as an internal card, or as an external adapter. Formats include the PC Card® style that resembles a thick credit card, or USB dongle. Both devices provide an RJ-5 port for connecting to an Ethernet cable.
Wireless adapters come in the same footprints as wired adapters. Wireless networking standards have evolved to include multiple protocols. A protocol can be thought of as the common language the router and network cards share in order to understand one another. A wireless LAN network adapter must support at least one common protocol with the router, or the devices will not be able to communicate. Two pervasive protocols are 802.11n and the older 802.11g. Newer protocols are generally faster and more robust than previous standards.
A LAN network adapter uses a device driver to interface the hardware with the system. The device driver or software tells the computer how to utilize the hardware. Most devices come with a device driver, but they can typically also be downloaded.