Which of the following statements is true about MAC addresses?

MAC addresses, or Media Access Control addresses, play a crucial role in network communication by serving as unique identifiers for devices on a local network. Each network interface card (NIC) or network device is assigned a MAC address, which is a permanent address that allows devices within the same local area network (LAN) to recognize and communicate with each other.

Unlike IP addresses, which can change based on the network environment (e.g., when a device connects to different networks), MAC addresses remain constant, providing a consistent identifier for the device. This consistency facilitates reliable communication and ensures proper data transmission within the network.

The other statements do not accurately reflect the nature of MAC addresses. While some devices might have the capability to change their MAC addresses for security purposes, this is not a fundamental characteristic of MAC addresses as a whole. Additionally, while MAC addresses are generally static for a device, they can sometimes be altered, which contradicts the assertion that they are always immutable. Lastly, the comparison of MAC and IP addresses in regards to transmission speeds is not a relevant distinction; both serve different roles within the network stack, with MAC addresses functioning at the data link layer and IP addresses at the network layer.