What does a network card do?

A network card, also known as a network interface card (NIC) or Ethernet adapter, is a hardware component that enables a computer or device to connect to a network. Its primary function is to facilitate communication between the device and a network, allowing data to be transmitted and received over the network.

Here are the main functions and roles of a network card:

1. Network Connectivity: The network card provides the physical interface between the device and the network, allowing the device to connect to wired or wireless networks. It has ports or connectors (such as Ethernet ports or Wi-Fi antennas) that establish the connection to the network infrastructure.

2. Data Transmission: The NIC handles the transmission and reception of data packets between the device and the network. It converts data from the computer into a format suitable for transmission over the network and vice versa.

3. Protocol Handling: It supports various networking protocols (such as TCP/IP, UDP, HTTP, etc.) necessary for communication on the network. The network card interprets these protocols to ensure that data is correctly formatted for transmission and reception across the network.

4. Data Link Layer Processing: The NIC operates at the data link layer of the OSI model and handles tasks such as framing, error checking, and controlling access to the network medium (e.g., Ethernet or Wi-Fi). It encapsulates data into frames and manages the flow of data between the device and the network.

5. Network Security: Advanced network cards may include features like encryption, authentication, and security protocols to ensure secure data transmission over the network and protect against unauthorized access or data breaches.

6. Speed and Performance: NICs can vary in their speed capabilities (measured in Mbps or Gbps) based on the type and specifications. Higher-speed network cards can handle larger volumes of data, improving network performance.

7. Driver Interface: To function correctly, a network card requires specific device drivers installed on the computer's operating system. These drivers facilitate communication between the operating system and the network card, enabling proper configuration and control of network settings.

In summary, a network card serves as the interface between a computing device and a network, enabling communication, data transmission, and interaction with other devices and resources on the network.