Network interface cards, often referred to as NICs, are computer add-in cards that provide inter-networking capabilities for a specific computing solution. There are many types of NICs that are used in varying situations. The largest deviation between cards is based upon their connective medium and speed capabilities. To a lesser extent, NICs can be differentiated by their type of connectivity to the computer itself.
10/100 Ethernet cards are networking cards that are used most frequently in the home or small office setting. As the name suggests, they are capable of speeds up to 10 or 100 megabits per second, not to be confused with megabytes per second. These cards usually connect to the computer using a PCI, PCIe or ISA motherboard interface slot. These cards are setup to use category 5 or 6 networking cables. The difference between category 5 and 6 networking cables is the addition of more shielding in category 6 cable to reduce "cross-talk" that slows network transfer speeds.
Gigabit Ethernet NICs provide network transfer speeds of up to one Gigabit per second. These cards connect to the computer using the same means as previously mentioned, however, they are much more likely to be produced for PCIe slots. These NICs can utilize Category 5, 5e, 6, and 7 cabling, with a preference for the latter. However, these NICs are more often made to utilize fiber optic cables for use in enterprise solutions such as web servers or data storage centers.
Major network infrastructures such as tier 1 and 2 Internet backbones require much more powerful NICs. Fiber optic NICs use fiber optic cabling to reach speeds of 10 gigabits per second currently, with a specification under review to push this limit to 100 gigabits per second. These NICs are often, though not always, external devices that connect to servers or workstations via an inter-networking plane which provides a lower connective speed to individual devices, such as 100 Mb/s. These NICs are a considerable financial investment and require much service and maintenance.
Wireless networking has become very popular in the last few years, as of 2009. Wireless NICs provide the same networking capabilities as their wired counterparts, however, they have their own transfer capabilities. Speeds of 54 Mb/s are the most commonly available to wireless NICs without teaming several NICs together to combine bandwidths. These NICs, however, provide for wireless networking that allows for more freedom in computer topology and installation.
There is a wireless networking device used by individual machines that have access to a main computer that is connected to a wireless router. This wireless router allows the user to install wireless dongles instead of entire routers with each additional machine on the network. These devices may connect via ether connectors to a standard Ethernet card, however, they are most prevalent in a USB compatible connective specification. This connectivity through USB allows for real time plug and play installation without the financial burden of purchasing multiple wireless routers per machine.