Network Interface Card (NIC)

Network Interface Card (NIC)

A network interface card (NIC) is a hardware component, typically a circuit board or chip, installed on a computer so it can connect to a network.

The network interface card function is to facilitate communication between a computer/server and a local area network (LAN), wide area network (WAN), or the internet.

A NIC provides a computer with a dedicated, full-time connection to a network. The NIC operates as a middleman between a computer and a data network.

For example, when a user requests a webpage, the computer passes the request to the network card, which converts it into electrical impulses. A web server on the internet receives the impulses and responds by sending the webpage back to the network card as electrical signals. The card receives these signals and translates them into the data that the computer displays.

Network controllers were originally implemented as expansion cards that could plug into a computer port, router or USB device. However, more modern controllers are built directly into the computer motherboard chipset.

While the standard NIC is a plastic circuit board that slides into a computer to connect with the motherboard, this connection can occur in multiple ways. Some types of NICs include the following:

1. Wireless. NICs that use an antenna to provide wireless reception through radio frequency waves. Wi-Fi connections use wireless NICs.
2. Wired.  NICs that have input jacks made for cables. Ethernet is the most popular wired LAN technology.
3. USB. NICs that provide network connections through a device plugged into the USB port.
4. Fiber optics. NICs used as a high-speed support system for network traffic handling on server computers. It’s also possible to achieve this support by combining multiple NICs. Fiber optic NICs are typically more expensive and complex.

NIC components

Components of NICs include the following:

1. Speed. All NICs have a speed rating in terms of megabits per second (Mbps) that determines the card’s performance in a network. The average Ethernet NICs come in 10 Mbps, 100 Mbps, 1000 Mbps and 1 gigabits per second varieties.
2. Driver. The required software that passes data between the computer’s operating system and the NIC.
3. MAC address. Unique, unchangeable media access control addresses, also known as physical network addresses, are assigned to NICs.
4. LED indicator. Most NICs have an LED indicator integrated into the connector to notify the user when the network connects and data transmission occurs.
5. Router. A router is sometimes needed to enable communication between a computer and other devices. In this case, the NIC connects to the router which is connected to the internet.