Which device is commonly used for connecting multiple devices in a local area network (LAN)?

A switch is commonly used for connecting multiple devices in a local area network (LAN) because it operates at the data link layer of the OSI model, allowing it to effectively manage data traffic within the network. It can intelligently forward data packets to the appropriate devices based on their MAC addresses, which minimizes collisions and enhances network efficiency. Each port on a switch can learn the address of the device connected to it, maintaining a MAC address table to ensure that data goes directly to the intended recipient without unnecessary broadcasting to all devices on the network.

In contrast to a switch, a hub connects multiple networked devices but does so without the ability to filter or direct traffic; it simply sends incoming data packets to all ports, regardless of the intended recipient. A router connects different networks and routes traffic between them, which is not its primary function in a LAN context. A modem, on the other hand, modulates and demodulates signals for data transmission over telephone lines or similar mediums, serving as a gateway to the internet rather than facilitating communication between devices within a LAN. Thus, while all these devices play important roles in networking, the switch is specifically designed for efficient intra-network communication among multiple devices in a LAN setting.