HTTrack is a Free/Open Source program that can copy a website to your local hard drive. You could set it up to copy a small website or even a huge website, but I would caution you from downloading a site with gigs and gigs of data. The program has some settings you can change but for the most part out of the box it’s ready to go.
Why would you copy a website 1.) To show people how a website works, 2.) To Grab all images out of folders. I could give you many more reason but lets just stop here. As you look at the HTTrack website there are alot of things from documentation, FAQ information, to how not to use this program.
The following video is one I found on youtube Mike explains this pretty well the video is about 4 1/2 minutes enjoy:
Video by: Mike from Northern Kentucky University