What is NIC?

A network interface card (NIC) is a hardware component that helps a computer communicate with its networks. It is the core hardware for network connectivity and is usually a chip or circuit board installed on a computer. NICs are present in all network devices and most other endpoints, including desktops, laptops, servers, and printers. An NIC is also known as a network interface controller, network adapter, network adapter card, Ethernet card, Ethernet adapter, or LAN card. NICs facilitate communication between a computer and other network devices through buses. They support most of the standard buses, providing flexible communication across varied devices.

Why do we need NICs?

Communication between devices and networks can happen only when NICs are present, so it is crucial to have an NIC in a device. NICs facilitate both wired and wireless communication. Furthermore, they help in communication when multiple systems are connected to a central network, and when there is a paired system-to-system connection as well. An NIC also helps computers communicate within a LAN and is useful for large-scale computers connected through an IP.

Components of an NIC

The following are the components of an NIC:

  • Memory: External memory is used to store data temporarily and process communications.
  • Driver: A driver is software that transfers data from the computer's OS to the NIC, and vice versa.
  • MAC address: A MAC address is a unique, physical network address assigned to the NIC; Ethernet packets use this address to communicate with the computer.
  • Controller: A controller is a processing unit that processes the data received. It converts a data message into a signal format.
  • Router: A router establishes communication between a computer and other devices.
  • Bus interface: This interface serves the connection between the NIC and the computer.

Types of NICs

Based on the network connection, NICs are classified as wired and wireless NICs. USB-based NICs and fiber optics NICs are available as well.

There are also different types of NICs categorized based on port type, transmission speed, bus interface, and device type (server or computer).

How does an NIC work?

NICs simply act as interfaces at the TCP/IP layer. They transmit signals at the physical layer and packets at the network layer. NICs act as a bridge between a server or network device and a network. If a router is plugged in to the NIC slot, then it acts as the bridge between the network and the multiple devices connected to it.

The bits received are formatted into frames. The cyclic redundant code algorithm is used, and the MAC address of both the source and destination are verified. After this, packets are created and transmitted using different network protocols for further processing.

Advantages of NICs

Data exchange:

NICs make data exchange between different systems possible. They facilitate wired and wireless communication.


NICs aid in quicker communication in a network.


NICs are secure and reliable. The MAC address provides identification and is unique.


NICs are inexpensive and easily available in the market.

Disadvantages of NICs


Not all NICs are portable.


NICs need to be configured properly. While procuring an NIC, an admin must purchase one that matches the system configurations and network speed, and then the NIC must be configured accordingly.

NICs form the basis of any network operation, so it’s crucial for network admins to monitor them. Even in a virtual environment, NICs have to be closely tracked to understand network communications.

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