switch

A switch is a device that performs switching. Specifically, it forwards and filters OSI layer 2 datagrams (chunk of data communication) between ports (connected cables) based on the Mac-Addresses in the packets. This is distinct from a hub in that it only forwards the datagrams to the ports involved in the communications rather than all ports connected. Strictly speaking, a switch is not capable of routing traffic based on IP address (layer 3) which is necessary for communicating between network segments or within a large or complex LAN. Some switches are capable of routing based on IP addresses but are still called switches as a marketing term. A switch normally has numerous ports with the intention that most or all of the network be connected directly to a switch, or another switch that is in turn connected to a switch.
Switches is a marketing term that encompasses routers and bridges, as well as devices that may distribute traffic on load or by application content (e.g., a Web URL identifier). Switches may operate at one or more OSI layers, including physical, data link, network, or transport (i.e., end-to-end). A device that operates simultaneously at more than one of these layers is called a multilayer switch.
Overemphasizing the ill-defined term "switch" often leads to confusion when first trying to understand networking. Many experienced network designers and operators recommend starting with the logic of devices dealing with only one protocol level, not all of which are covered by OSI. Multilayer device selection is an advanced topic that may lead to selecting particular implementations, but multilayer switching is simply not a real-world design concept. Switch 5530-24TFD is a next-generation stackable 10/100/1000/10000 Mbps Ethernet Layer 3 routing switch designed to provide high-density Gigabit desktop connectivity and Gigabit and 10 Gigabit fiber connectivity for aggregation for mid-size and large enterprise customers’ wiring closets. It combines higher flexibility of deployment using Gigabit copper or fiber connections coupled with exceptional performance utilizing dual 10 Gigabit uplinks.
The Ethernet Routing Switch 5530-24TFD provides with 24 10/100/1000BASE-T RJ-45 ports, 12 shared Small Form-factor Pluggable (SFP) slots, and 2 slots for 10 Gigabit Ethernet Small Form-factor Pluggable (XFP) modules. The switch includes two built-in stacking ports in a compact 1 rack-unit high design. The Ethernet Routing Switch 5530-24TFD may be utilized in standalone mode, or may be stacked together in a mixed stack of 8 units with existing Ethernet Routing Switch 5510-24T/48T or 5520-24T/48T-PWR devices.