Please, spread the word. As most of you know, and to those that don't: you need a spanking, there is a marked difference between the two.

Throughput is the amount of information (pulses, bits, frames, packets, etc...) that can be sent through a conductor while it is under the stresses of real-life operation. These include improper wiring (crossed pair, anyone?), EMF or Magnetic Flux disturbances and noise, the Johnson's dog digging up your backyard, or plain old-fashioned, good old American collisions.

Bandwidth is the amount of information it is physically possible to send through the media of choice (copper, fiber, the Johnson's dog). This is the number you get when you sit down with your trusty TI-82 and the impedence charts from Physics and calculate out how many bits per second can be sent through a foot of copper/fiber/whatever.

The relationship can be roughly described as Experimental vs Measured