Running Display Traffic

Thanks in advance for help.

I'm getting asked about promotion methods running display traffic. I'm a bit new to running things through display. Can anyone explain the various ways one can run traffic through display?

I was asked something about if I was purchasing the traffic... what are some good, legitimate sources to do this? Pros and cons?

Can any plz explain me that what is display traffic :s

Display Traffic refers to the traffic generated from flash ads or banner ads.

I got the info by Googling.