can anyone pleease describe what hubs, bridges, switches and proxy servers are and what are they used for
pleease reply quickly
thanks
A hub is a device that connects a number of computers together to make a LAN.
The typical use of a hub is at the centre of a star network (or as part of a hybrid network) - the hub has cables plugged into it from each computer. A hub is a ‘dumb’ device: if it receives a message, it sends it to every computer on the network. This means that hub-based networks are not very secure - everyone can listen in to communications. Hubs are pretty much obsolete now (you can't buy them any more), having been superseded by cheap switches.A switch, like a hub, is a device that connects a number of computers together to make a LAN.
The typical use of a switch is at the centre of a star network (or as part of a hybrid network) - the switch has cables plugged into it from each computer.
A switch is a more ‘intelligent’ device than a hub: if it receives a message, it checks who it is addressed to, and only sends it to that specific computer. Because of this, networks that use switches are more secure than those that use hubs, but also a little more expensive.
A proxy server is a computer setup to share a resource, usually an Internet connection.
Other computers can request a web page via the proxy server. The proxy server will then get the page using its Internet connection, and pass it back to the computer who asked for it.
Proxy servers are often used instead of router since additional software can be easily installed on the computer such as anti-virus, web filtering etc.
A bridge is a network device that typically links together two different parts of a LAN. Whereas a router is usually used to link a LAN to a WAN (such as the Internet), a bridge links independent parts of a LAN so that they act as a single LAN.
