Which device is used to connect multiple devices on a network and manage traffic?

The device that is used to connect multiple devices on a network and manage the traffic among them is a switch. A switch operates at the data link layer of the OSI model and efficiently receives, processes, and forwards data to the appropriate destination within a local area network (LAN). It maintains a MAC address table to keep track of the devices connected to it, allowing for quick and accurate delivery of data packets to the intended recipient device.

In a network, the switch enables communication between devices like computers, printers, and servers by directing data only to the port of the destination device instead of broadcasting it to all ports, which enhances both performance and security. This targeted delivery helps to reduce unnecessary network traffic and improves overall network efficiency.

Each of the other devices mentioned serves different functions within a network. A router connects multiple networks and directs data between them, often incorporating additional features like NAT and DHCP. A modem connects a network to the internet, converting digital signals to analog for transmission over phone lines or cable. A firewall is designed to protect a network by controlling incoming and outgoing traffic based on security rules but does not manage the internal traffic among connected devices.