Network Interface Card: What Is It and Where to Buy One

Key takeaways

• A network interface card (NIC) enables wired or wireless communication with local area networks or a larger network.

• Network interface cards act as translators by converting your computer’s requests, such as visiting a website, into data packets that the network can understand and process.

• Ethernet NICs are among the more commonly used network interface cards.

The two main types of NICs are internal NICs that are built into a device and wireless NICs that provide wireless connectivity for laptops and other portable devices. Learn more about the network interface card, including its components, working mechanism, and explore tips for selecting the right NIC.

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What is a network interface card?

The network interface card, or NIC, is hardware installed in your computer that lets you connect your devices to communicate over a computing network or servers. It provides wired or wireless communication with local area networks (LANs) or with the large-scale network through the internet protocol (IP). NIC cards work on the open systems interconnection (OSI) framework's physical layer (layer one) and data link layer (layer two).

The NIC circuitry communicates with the physical and data link layers to connect you to the network. These cards are sometimes called network interface controllers, network adapters, or LAN adapters.

How do NICs work?

Think of the NIC as a translator. Whenever you visit a website or send an email, your computer sends a request for that information. The NIC takes that request and converts it into a language that the network can understand. It packages the request into data packets and sends them over the network.

It receives packets from the network, breaks them into understandable pieces, and sends them to your computer. This action lets you see web pages, receive emails, or download files.

Every NIC has a media access control (MAC) number, a unique identifier assigned by the manufacturer. The MAC identifies the NIC's computer on the network. Some confuse the NIC with a broadband or internet card, but broadband cards connect your device wirelessly to a network. A network interface card connects to a router or network switch via a direct connection.

What are the two types of NIC?

There are two main types of network interface cards: the NIC that comes included internally with your device, and a wireless NIC found in laptops or other portable devices. The latter connects to Bluetooth or Wi-Fi using an antenna to communicate using radio waves to allow wireless communication between the device and broader networks.

When your internal NIC isn’t enough, an external network expansion card improves connectivity speed and reliability and expands the device’s connectivity.

What is an example of a network interface card?

An Ethernet NIC is one of the most widely used network interface cards. It can receive/send and assemble/disassemble data to and from a network connection.

NIC components

The NIC has six parts. Each plays a role in the card’s translator role.

• Controller: The processing unit that decides how the NIC performs

• Boot read-only memory (ROM) socket: Enables the card to store instructions for its function permanently

• NIC port: Typically connects to an Ethernet cable to transmit and receive signals

• Bus interface: Connects the card to the expansion slot for the device it serves

• LED indicators: Indicators that help identify the card’s status in the connected network

• Profile bracket: Helps affix the NIC in its slot on the computing device

What is an example of a network interface card?

An Ethernet NIC is one of the most widely used network interface cards. It can receive/send and assemble/disassemble data to and from a network connection.

When and where to use a NIC

Network cards can provide quick, efficient, and secure communication, making the wired NIC connection a popular choice in homes and professional settings. Traditionally associated with desktops, laptops, and servers, NICs can also be found in printers, scanners, smartphones, smartwatches, and other connected devices.

Many users are unaware that the NIC is in their device as it’s part of the computer hardware. If you customize your network or server configuration or build your own computers, you will likely pay more attention to your choices when buying and installing NICs.

Read more: What Is the Internet of Things (IoT)? With Examples

Where and how to buy a NIC

You can buy network interface cards at several locations online, like Amazon, Newegg, Best Buy, and Office Depot. With so many types of NICs for various buses, ports, connection types, and different networking speeds and operating systems, prices range from about $20 to $200. Follow these steps for some tips on how to buy the best NIC for you:

1. Choose the appropriate bus: To do this, look at the slots on your device or research the connection in the manual. The primary options include PCI, PCI-X, PCIe, and USB.

2. Now, you can select your NIC speed: You’ll typically be looking at 10/100/1000 Mbit/s NICs. That means they can transfer data at 10, 100, or 1000 Megabits per second. Some NICs even support 10, 25, and 40 Gigabit connections. The bus you choose can limit your speed options, so select the NIC card that can support your network needs.

3. Choose the number of ports: A card can have one or more ports, which may prove useful if you have a particular networking need. Typically, you’ll choose from one, two, or four ports.

4. Consider how the card will connect: You can pick from several options, including Ethernet, direct attach copper (DAC) cable, multi-fiber push-on (MPO), multi-fiber termination push-on (MTP), and more.

5. Confirm your choice works with your operating system: Many NICs work with several systems, but always check first.

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