How to use wget to download a file

As i know you cannot download wget to download files from the web sites which needs authentication or human verification.

but most of the times you can directly get the URL of the file,
open a terminal and type (without [])

wget -drc [URL]

if you need to pass from a proxy if you did not set the proxy address yet

 
export http_proxy="[url]:[port]"

example

export http_proxy="http://cache.pdn.ac.lk:3128"