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Layer 1 (Physical): Hub and Repeater - These devices take in traffic from one port and broadcast out all others (a repeater is basically a specialized version of a hub, with just two ports).
Layer 2 (Data Link): Switch and Bridge - These devices look at the MAC address and build a table of which port on the device has which MAC address. If it recieves a packet addressed to a MAC addy it doesn't know, it sends this out all ports except the one it recieved it from. A bridge is a specialized switch, with just two ports. (Advanced knowledge: Switches seperate collision domains and are used in microsegmentation, but that's probably not what you're asking).
Layer 3 (Network) - Routers and multilayer switches - Routers are used to choose the "best path" for a packet to travel, based on the destination IP and static routes that may be configured within the router itself. Multilayer switches are somewhat dumbed down versions of routers that operate on a simpler scale. They look at the IP and send to the corresponding port, but are faster switching packets in small networks, as they do all of the necessary computation in hardware, rather than software.
Layers 4-7 - You can have routers that forward packets depending upon information the packet carries in layers 4 through 7. These are normally used in QoS (Quality of Service) applications to ensure that, for example, the video conference between the corporate headquarters and the district offices recieves highest priority and thus doesn't suffer from bandwidth issues, while restricting traffic destined for Kazaa to have little to no bandwidth.
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